What is the correct size bottom drain for my koi pond?

[@maleok2569]

This helped me tremendously, thankfully the pond I'm building I qualifies for the 4" that everyone recommends but I'm going to retrofit my first DIY pond (everyone mucks up their first time) to about 800 gallons or 3000 liters and I'm going to install a smaller bottom drain system, with the *correct* pipe size now because of this.

[@DazzleKoi]

Sounds good mate and thank you. They certainly do, mine was awful. I eventually fixed the issues and used it as a fry tank once I'd built my second pond much better 🍻🍻

[@TelfordKoiPond]

I hadn't really given the size of the bottom drain any thought , just presumed 4" would be best in all situations. I'll be running about 11,000 to 12,000 lph so believe I'll be OK with the 4" I've got installed .....phew!! Another great and informative video.....thank you, keep them coming.

[@DazzleKoi]

Hi mate, yes you should be ok with that flow. As someone said above though, if you can do it its a good idea to add a means of flushing the line. Its better to have it and not need it than to need it and not have it 👍👍

[@KoiRun50]

You have a special knack for explaining things clearly.

[@DazzleKoi]

Thanks mate , I really appreciate that. I must admit it doesn't feel like it to me but that is reassuring 🍻👍🍻👍

[@anthonywatkins2783]

For anybody building a new pond that is very valuable advise, looks cold up there, very useful video AGAIN 👍

[@DazzleKoi]

Thanks mate, to be honest I didnt realise I was shivering until I watched it back 😁

[@AndreSilva-lx8dv]

Hello. I'm building my new pond and this video clarified many doubts I had. Excellent explanation. Congratulations for all your videos. Greetings from the Azores islands, Portugal.

[@DazzleKoi]

Hi mate, and thank you very much. It still amazes me how far and wide youtube videos reach. All the best 🍻🍻🍻

[@andycox3862]

Great subject 👍 most people don't give the bottom drain much thought after fitting it my pond is a tad smaller than yours and I used a 4 inch bottom drain ,but I kept it as short as possible at about 1 metre long and goes in the filter at 4inch ,so when I clean the filter I also purge the bottom drain. Keep up the good work my friend 👍👍👍👍👍👍

[@DazzleKoi]

Sounds good mate 🍻👍

[@MickysAquariums]

Im glad i watched this before i put my bottom drain in. Lots of useful info! Thanks 👍

[@DazzleKoi]

Thanks Micky, good to know it helped 🍻👍🍻👍🍻

[@simongates8186]

Great video Daz, I’m just about to build my first pond at about 6800litres and have ordered a 3” bottom drain for an easy pod and was second guessing myself. This has made me feel much better about the decision.

[@DazzleKoi]

Thanks Simon, that's good to hear 🍻👍🍻👍🍻

[@ThePondAdvisor]

This is a great topic, 90% over looked by most koi pool builders. Bottom drains must be flush, like a toilet, a 4” bottom drain ran at 5000 litres per hour is only using 10% of the capacity of the gravity flow able to run out the other end.

[@ThePondAdvisor]

155,400 litres per hour can run through ridged 4’ PVC at high pressure, if it’s flexible PVC like we tend to use (we don’t install bottom drains however) this is reduced by 3%

[@DazzleKoi]

Thats true mate and just to clarify so no confusion, you are talking about pumped flow (under pressure as you say) , gravity flow is much much smaller, closer to 18,000 to 20,000 litres max in most pond conditions.

[@jimwoollard8329]

Great video. It's something a lot of people wouldn't think about. I would recommend having a method to flush straight to waste even if you have calculated the flow correctly. I've also seen people add access ports so they can use cleaning rods. I think you would need to be very careful doing that. The last thing you would want is to get brushes or such like stuck in your pipework.

[@DazzleKoi]

Hi Jim, yes a good point that, if you can do both its got to be even better 👍👍

[@barrykoikeepercooper8052]

My pond is 2,000gallons its a tank with a 4inch bottom drain I have a pipe that we once a week purge our drain out and the muck that comes out that purge is unreal in summer more so. Thanks for another great video pal 👍 👍

[@DazzleKoi]

H Barry, good to see you have the means to purge and that you see a lot of muck come out. If that purge didn't happen you can imagine how much debris would build up and the potantial for bacterial issues it presents 👍👍

[@garydrablow853]

Very useful information that is clear and concise

[@DazzleKoi]

Thanks Gary, that means a lot. Stay safe Sir 👍👍🍻🍻👍👍

[@paulf9064]

Dazzler😀, your video's are a wealth of information Sir. In depth, to the point but still really easy to understand. Thank you, a great help to many im sure 👍🏻

[@DazzleKoi]

Thanks Paul, I really appreciate that Sir 👍👍🍻🍻👍👍

[@waynebrown5852]

Im a koi keeper of 25+years and have been a advocate of having a good pull on the bottom drain on my system it pulls 200 litres in one pull l have seen a lot's of drum filters with no purge on them, i like the drum filter but there is not a big enough water volume in them to clean out the pipe work, happy New year

[@DazzleKoi]

Hi Wayne, I haven't a lot of experience with drum filters but that sounds like a worry. I take it that some have purge capability them? but some don't?

[@djbanger]

You look like your freezing 🥶 great vid as always!

[@DazzleKoi]

I think I need to put a coat on next time, or go inside 😁

[@darrenjones1564]

Hi mate. Another well put together vid. I built my first ever pond in 2019 and never put a bottom drain , before I even put water in it I was regretting not putting it in it will be a job for the future . A pond vac is a must with a pump fed and for Christmas I got a upgrade vac , a oase pondovac 3 it's a boody good tool for the pond👍👌

[@DazzleKoi]

Hi Darren, yes I get stick for saying a bottom drain is vital for a koi pond and I can appreciate that is a bit extreme and not strictly true but the difference it makes is huge. I just don't want people to underestimate how big a difference it makes. Back when I was pump fed I had a pondovac, they are brilliant vacuums. I think mine was the first incarnation and it was great so I can only imagine how good the newer models are 👍👍 You can make pump fed work for you just as well as gravity, it just needs a LOT more work.

[@darrenjones1564]

@@DazzleKoi when I built the pond I just went off a guy's advice with the bottom drain or not the bottom drain should I say. Now I'm getting into the whole pond thing and not just the fish it makes sence that i f###ed up😳 lol. .

[@DazzleKoi]

Don't worry about it mate, its all good experience. I don't know anyone who has got it right first time. It gives you a good excuse to build another one, BIGGER !!

[@darrenjones1564]

@@DazzleKoiwell hell yeah I'm all ready collecting stuff for that lol. I've just bought compact sieve 2 and its here so I will be fitting that when it warms up I'm sure the lph rating they given is a bit much .

[@DazzleKoi]

Yeah you can take most filter manufacturers figures with a pinch of salt. Best to try and ask people who have used them at home if you can

[@cookoi]

Great info for a new pond builder 👍

[@DazzleKoi]

Cheers mate, thanks for taking the time to comment to 👍👍🍻🍻

[@IcenI_Koi]

Very interesting Daz, seen loads of folks recommending 4". Not necessary. Stay safe & well buddy.

[@DazzleKoi]

Thanks mate, you too 🍻🍻

[@davewraxall8021]

Phenomenal!!! You are the only person (besides me!), who I have come across who has spoken about this extremely important subject. One the koi channels, I was constantly advising people to keep their systems squeaky clean, to avoid bacterial issues, the cause of those ‘mysterious’ deaths which leave you scratching your head. I’m planning a new pond and I am going to set my bottom drains so that they can be individually flushed directly to waste, in a straight line, to give me the maximum flow, to clear and debris, using a ball/slide valve. When the valve is closed, the water will flow up to an RDF. If you aren’t already, you should get on the Pond Owners’ channel on FB. They desperately need someone who has got a clue, to offer good advice. There is an extraordinary amount of crap advice flying about and your common sense, easy to understand approach would be excellent. I got banned from FB completely, for kicking off about all the CV nonsense, so I can no longer chuck my 10 cents in. You offer your advice and qualify it and that would be invaluable to the newbies on the forums and a lot of the self proclaimed ‘experts’ too. On the plus side for you, it will increase your exposure. Don’t hide your light under a bushell!

[@DazzleKoi]

Hi Dave, thanks very much, I really appreciate you taking time to give your input 🍻🍻 I'll check out that on Facebook, thanks 👍👍

[@madmikesworld5713]

We have a well known member of the koi fraternity who has just died of covid. Perhaps any thoughts about covid is best left off a koi related post.

[@countrykoipond]

I am using the 4" slow flow and big weekly flush technique. The key to it is flushing regularly and keeping the valve open just long enough to clean the sediment through without wasting too much water!

[@DazzleKoi]

Yes that's very true 👍

[@markmoulton3521]

Another great video - superb tips 👍

[@DazzleKoi]

Thanks mark, I appreciate that 🍻🍻

[@madmikesworld5713]

When looking at pipe work you need to look at your filter and the volume of the pond. How much water needs to flow through your media to optimise efficiency. To little or to much will have serious effects on your good bacteria’s feeding habits. You shouldn’t go wrong in choosing pipe work as it does become obvious what you need. A bloody good point on restriction of pipe work going into filters as the flow drops massively from let’s say 100mm to 50mm pipe work.

[@DazzleKoi]

Cheers Michael 🍻🍻

[@CATANDEYEKOI]

Well structured and well explained. Thank you.

[@DazzleKoi]

Thanks mate, I really do appreciate that. Stay safe Sir 👍👍👍

[@Tillygoat60]

Another great topic thanks buddy

[@DazzleKoi]

Cheers Rex, I appreciate your taking time to comment as always, take care 🍻🍻

[@edylie007]

I am building a pond now and the size is 4mx5mx90cm deep. What is the recommended bottom drain 3” or 4”? I would have a pump in the sendiment tank to pull all this into a RDF. That pump is rated at 12000litres per hour.

[@DazzleKoi]

Hi mate, you really should match your drain to your filter flow rate which you haven't said but I'm guessing its going to be quite high if you are fitting a drum. Anything over 6000 litres and you really need a 4". If its only just over 6000 I would consider fitting a purge valve so you can purge your drain line out regularly.

[@chrisreed2285]

Thanks for the advise...using a nexus 310 unused

[@DazzleKoi]

No problem Chris, great filter and high enough flow rate to run a 4" drain without to much settlement 👍👍👍

[@thefearlesspict9794]

Hi dazzle would you recommend using 2 3” bd’s on a 4000 gal pond?

[@DazzleKoi]

Hi mate, its in that grey area really but I would go for 4" and run 2 filters if possible. I had 2 nexus 220's on a pond of this size in the past and it worked well. Its imperative that both drains pull exactly the same flow.

[@deanmurney1283]

Thanks for this video, i am currently building a koi pond that will be 6,355.7 litres its my first build with no experience and the plumbing as had my head baffled due to what size bottom drain.

[@DazzleKoi]

Hi mate, yeah it can be a minefield of dodgy information out there. Take your time and do your research and you'll be ok. Its good if you can visit people who are running similar sized ponds and see them yourself to 👍👍

[@keithcowburn4715]

Another very informative and interesting video. With the nexus after the initial clean I think most do a second clean which involves a flush which I assume will (hopefully) get rid of any nasties in the pipework. An important factor to me, and maybe one you could touch upon in a future video, is the flow rate. I can't comment about other types of filters but with the nexus I think the flow rate is critical to the efficiency of the media in terms of removing ammonia etc.

[@DazzleKoi]

Hi Keith, yes as long as you have the full 4" going in to the nexus with no reductions then you are getting a decent purge each time you refill after a clean 👍 Regarding the flow rate, yes off the shelf all in one filters all have an optimum flow rate where they perform at their peak. Its a trade/balance between mechanical and biological performance usually. I do place great emphasis on getting this right (5500 litres an hour for the Pod for example) but I haven't made a video specifically on optimum flows for the popular filters. I will add that to the list and visit that in the future though, thanks 🍻🍻

[@keithcowburn4715]

@@DazzleKoi When I first got the nexus I enquired with Evolution Aqua about the flow rates and they recommended that the entire gallonage of the pond go through every 2 hours...so on a 10,000 litre pond the flow rate would be 5,000 litres an hour. I've stuck with that advice although I'm not convinced its as simple as that. When starting the filter up I think its important to not exceed that flow rate but once the media becomes mature there could be a case to increase the flow rate but maybe by not too much. As you say its a balancing act and although it would be nice to have a high flow rate we don't want to do that to the detriment of the biological performance.

[@DazzleKoi]

Hi Keith, yes that's very strange advice in my opinion. The filter doesn't know how many gallons your pond is and the optimum flow rate doesn't change no matter what size pond its on. I would be increasing that flow if it where me, to around 6000 litres and observing your water for a month or two. Biologically it will be fine but I would expect some improvement in clarity. That said, if it aint broke dont fix it comes to mind so if you are happy with the performance it might be best to just leave it alone.

[@keithcowburn4715]

@@DazzleKoi Any future video you make could include advice on flow rates and also the amount of food to use. This is the reply I received from Mark Huyton from EA on these subjects: The 50 litres of K1 will allow you to feed around 250grams of food per day. The size of pump you need is related to the pond size, you should aim to circulate the water in the pond through the filter every two hours, so if your pond is 2400 gallons, the flow would be 1200 gallon (around 5000 litres) Mark Huyton

[@DazzleKoi]

Yes I'll definitely look at a video on optimum flow rates for the popular filters. Seems a very out dated and vague way of determining flow rate to me. Makes no sense at all. As I say, your filter doesn't know what size your pond is. You just want it to function at its optimum and if that doesn't do the job then you need a different filter.

[@richardc1983]

Hi Dazzle, I have a new pond its approx 1200l above ground. I am having some issues with the skimmer and bottom drain. I reused my Blagdon amphibious IQ 3000-6000 as I only bought it a year ago and wanted to try save some money where I could. This pump is doing both the bottom drain and the skimmer. It does one of them perfectly but it is struggling doing both. I cannot get the flow rate fast enough through the skimmer for it to move it to pull the surface water through and the bottom drain could be better when both are pulling water. I have the pump running at full tilt 35w which is the maximum it can go. I think the pipework, dirty harry pre filter, then the bioforce are all creating additional resistance so doubt we are getting the 6000 flow rate anyway. The bottom drain and the skimmer are t’d into a solid piece of pipe that is 2.5” in diameter back to the Dirty Harry and then the pump. I notice that I can also only have the water level to the first slot on the skimmer as anything higher then there is just too much water flowing into the skimmer through the lower slot/s and so again there is literally no movement. The action from the water blade creates more surface movement and so surface dirt just go round and round. A lot of you may ask when I didn’t get separate pumps to do each, the reason is space. I literally have my pond stuff at the side of a planter hidden by plants etc that I pull out. I have literally no back yard space, and I wanted the bigger pond so I am more than happy to upgrade the pump but I need a solution that will be 1 pump doing both not 2. I am thinking of getting a 10000 pump which will give me an extra 4k flow rate or should I go for a 20000 which will be even more? My filter is a bioforce revolution 6000 and it is only meant to have up to 4000l going through it as the max flow rate and I don’t really want to have to buy a new filter as I am struggling for cash at the moment. In hindsight it seems I have made a mistake but I am not in a position (health wise either) to start cutting pipework and adapting it all. All the pipework is fitted and the pond is in place so I have to adapt what I have. I believe with the right size pump then I think things will be fine but a larger pump may not be good for the bioforce anyway? Your thoughts please if I may?

[@DazzleKoi]

Hi mate, sorry for taking so long, I'm still miles behind on comments after my holiday a few weeks ago. Yes there is no reason why one pump cant do both systems. You will need them piped up correctly and you really need a ball valve on each line so that you can restrict flow on one to send more to the other. to enable you to balance them properly. I would get a 10,000 and you dont really need a variable speed one, any 10,000 fixed flow should be fine. Then you need to measure the flow on each line (use bucket method) and use the valves to get the flow you want on each one.

[@richardc1983]

@@DazzleKoi bought a 10k pump, skimmer no different but bottom drain is really pulling now. I have a gate slider valve on my skimmer but the guy who installed and fitted my pond didn't fit one for the bottom drain so I can't reduce it down a tad to encourage more flow from the skimmer.

[@DazzleKoi]

Hi mate, have a look at the height that your bottom drain lid is set to. It should be 12mm - 15mm. If you can lower it a little bit it will restrict the intake down, similar to closing a valve.

[@richardc1983]

@@DazzleKoi yep it's the lowest it can lower down to. Do you have somewhere I can send some pics of the pond to so I can show you my setup?

[@DazzleKoi]

Yes mate, send them to my email address, [e-mail]

[@garyneo2259]

hi m8 another great video. in the winter i used to clean my nexus 200 once a week in the winter. twice a week in the summer i have now started to clean the nexus every other day after watching your video been doing this for 4 weeks now i know it is winter but i have noticed a difference in water quality and the fish seem to be great. when cleaning the nexus wont the purge on the clean cycle keep the 4inch bottom drain clean regards gary

[@DazzleKoi]

Hi Gary, good stuff mate, it really does make a big difference if you can get the waste out as often as possible. It depends how you plumbed it, if the 4" line goes directly in to the nexus without being reduced anywhere then it will. I can't remember what size the inlet is on a nexus 200?

[@garyneo2259]

@@DazzleKoi 4inch straight to nexus

[@DazzleKoi]

Yes if thats the case you are purging the drain quite well when you refill the nexus after a clean 👍

[@Technologyadvisor1]

So I am just about to install a kockney koi skimmer box on my pond just wondering how best to install it. The skimmer box is around 1 inch above the main water level on my pond. well I hope it is the pond seems to be level know. So what advise would you give about fitting a skimmer ? the skimmer seems to be a 1/4 above what will be the water level. I in vision the water level of the pond will be about 1 inch below the top of the sleepers. Above that will be a capping piece of wood which is about 50mm in thickness. 1

[@DazzleKoi]

Hi hi, sorry for the delay. I've just watched your videos, good job so far mate 👍 Regarding the skimmer, I'm not really best placed to advise you if I'm honest as I don't really use skimmers. I've only installed them on one pond in the past and they where the full block skimmers so very different to yours. I've had a google about to and there isn't much out there on the kockney koi installation. I think its best if you ask the question on one of the facebook groups or forums. Sorry I'm not much help to you

[@jasoncoombs9309]

Hi Daz, I am really enjoying watching and learing useful tips. We are doing a self build early this year and have a question about the required base. You mention being a builder and wondered what spec your base was? We have builrt a farm track around 12" deep with fibre concrete no steel bars. It takes 15 to 20 tonne tractors with no issue, so would say 6" fibre concrete be plenty strong enough (maybe no fibre?). I have seen 8" steel re-enforced concrete used and just think this seems way over the top. Thank you for any information. Jason

[@DazzleKoi]

Hi Jason, what size pond are you planning? Its always a bit of a grey area this and 99% of ponds are built way over specced in my opinion. This little pond is built on approx. 5" with no reinforcing at all. My previous pond was 9 - 10" thick with fibres and was 5500 gallons. You need to consider the sub soil as well as the weight of water. Clay, which people think is hard and good for building on can actually move over time. Sand which seems softer and more fluid is actual good as it compacts and doesn't tend to move. Depending on the size of your pond, and assuming good sub base, 6" with fibres would be fine up to around 2000 gallons. Bigger than that 8" with fibres up to around 4000 gallons. Above 4000 gallons 10" with fibres. Im not really a fan of re-bar.

[@jasoncoombs9309]

@@DazzleKoi Thank you for that. We had a house extension done and the builder said we had some of the best sub-soil for foundations he had seen in a long while so I think when I get down a bit it will be good and firm. The plan is 7' by 16' and probably 5' deep which I think comes in around 3400 gallons. I do think fibres is the way forward and build the walls on ther base. I have seen people put a footing in then dig down but that seems like a recipe for cracks where wall meets base. Keep up the videos each one is well presented and clear.

[@DazzleKoi]

Cheers mate, sounds good, I much prefer fibres. I think it gives a different kind of strength if that makes sense. Its a lot easier and cheaper to which is a bonus. Yes definitely better to poor a base (make it a bit bigger than you need as its never square and you always lose some off the size getting the walls square on the base you have available) and build walls on that base then back fill.

[@richardbrunton2068]

Great information as per, cheers 👍

[@DazzleKoi]

Cheers Richard 🍻🍻

[@richardbrunton2068]

@@DazzleKoi what about bacteria home bakki shower media for the bakki shower build? I know it’s not gonna be as good as the genuine stuff but could be a decent and cheaper alternative. What’s your thoughts daz? Cheers 👍

[@DazzleKoi]

Hi Richard, yes I have that one on my list of medias to look at. Its turned in to a huge job this but I'll get through it all 👍

[@richardbrunton2068]

@@DazzleKoi cheers for reply daz, I see another name for that particular media is bakki house standard 👍

[@everliemamalias121]

Hi.i have a pond 7x4x3 ,what what bottom drain,should i get?and what subpump watt.i need? Thank u ,,from philippines

[@DazzleKoi]

Hi there, your bottom drain size will depend on what filter you are using and what flow rate it requires for best performance. Do you know what flow your filter needs?

[@Jeremydmeyer76]

I watched this video soon after you uploaded it. I haven't been able to sleep at night because I lay there trying to decide if I need a 4" drain. I'm right in the middle of my first build and it's around 3500 gallons. My pump will flow 6840gph. I am drawing from a 2" skimmer as well as the BD. The BD is connected to a Cetus Sieve and the skimmer directly to the pump. I've had 2 professional pond builders advise me. 1 says 3" with higher velocity is better and the other says I need a 4". I'm worried the 3 " will be the bottleneck and I'll have too much drawdown. I'm worried the 4" will flow too flow and it'll require more frequent flushing. How do I decide? Flip a coin? Also, I already have the 3" drain and plumbing ready to go.

[@DazzleKoi]

Hi Jeremy, I feel your pain. Firstly I need to clarify, you say 6480gph. Do you mean litres or is that correct? You couldn't pull 6480gph down a 3" drain, it would need to be 4". If you actually meant 6480 litres per hour, thats a little more difficult. What pump and filter are you using?

[@stephenwitt4121]

Another good subject. I have 8000 ltrs and a 4 inch bottom drain. I flush it about 3 times a week and you be amazed by the amount of muck that pulls through.

[@DazzleKoi]

Hi Stephen, is that 8000 litres flow or is that the size of the pond?

[@stephenwitt4121]

8000 is the size of pond. Running about 6000 per hour.

[@DazzleKoi]

ah ok, so yeah quite low on the range for 4". Good to hear you can flush it out and that you see plenty muck come out 👍👍

[@sweeyong7756]

ive got a 70.000l concrete pond 60m x 1.5m x 0.8 water depth through out the entire length. i would like to install a bd (not retro fit). would this be recommended and safe without comprimising the integrity of the structure. the plan is to drill out a sizable hole to install the bd, dig under the pond to install pipe, and pour concrete to fill the hole amd encase bd. what size bd is recommended. how many bd should be installed? flushing the pipe will be an issue as there is no drain that is lower than the depth of the pond. i will be relying on pumps alone. i plan to pump the water to a wetland filter 10 m long x 2m wide by 1.2 m deep at an elevation of 1m and at a distance of 35m from the bd outlet. my target is to turn over the water once every 12 hours which will work out to be 6000L p/h. sorry about the long post.. appreciate the kind advice.

[@DazzleKoi]

Hi mate, this is going to be extremly difficult to filter properly due to the shape. You would need at leats 5 bottom drains, the first one 10 metres from the end and then one every 10 metres after that. You would need at least a 6000 litres per hour pump on each drain (4" drains) to create enough suction. Then you need to return the water from the filter to the end with the 10 m etre gap to the first bottom drain to create water flow and movement towards the drains. Its going to be very difficult to get enough flow to push waste towards the drains though when they are spaced so far appart, they only really pull from around 2 metres so you need to move the waste to the drain with flow rather than rely on it pulling it in.

[@sweeyong7756]

@@DazzleKoi thanks mate. what are your thoughts on drilling a hole through the base concrete to install bd? i experimented with a 250watt sumersible bilg pump running 2 inch pipe hooked up to with 3 suction inlets (visible pipe work). i ran the water to an exisiting 19sqm wetland filter and the water quality improved heaps. it didnt pick up all the solids on the floor though. as you said, it needs more flow or turbulence to get the gunk towards the suction.

[@DazzleKoi]

Hi mate, yes installing a bottom drain in an existing concrete base is not as hard as you might think. Cut a channel and break up an area in the center for the drain. Dig out underneath and push the pipe through. then just set it all and pour concrete to replace what you have dug out. Its a bit of work but well worth it 👍👍

[@chrisreed2285]

Hi ..just your thoughts on new pond 12x8x5 ...would you think one 4” drain or poss 2x 3” drains...your advice would be appreciated...thanks

[@DazzleKoi]

Hi Chris, definitely 1 drain on that size and you'll need a 4" drain to supply a filter that can handle that volume. What filter are you planning?

[@sargent255]

Hello I am redoing my pond 14x16 " want to install bottom drain on a rubber liner what size drain should I use I have 5 Koi fish now but they are growing need to make bigger for them

[@DazzleKoi]

Hi Kelvin, the size of the drain is really determined by the filter system you are using. That is quite a big pond but you should be ok with just one drain in the middle. What filter are you going to have on it?

[@BettySwollocks13]

My pond is going to be 3.6m x 2m x 1m 6,480.0 litres (1,425.4 gallons) plus filter and pipework. Should i fit 2 or 1 x4" bottom drain?

[@DazzleKoi]

Hi mate, it depends really on what filter you are using. I'd be looking at something like a nexus 220 for that volume which is just about enough flow for a 4" drain.

[@StokeKoiAdventures]

Could I put a 3” reduced direct in the bottom drain so it’s 3” all the way through.

[@DazzleKoi]

Hi Neil, yes mate, as long as the reducer is before any 4" pipe, i.e. in the socket on the drain itself, it would work just the same as if you had a 3" drain 👍👍👍

[@jameshayton8469]

Hi Daz, great video, where is the best shop for all the pipe work and bottom drains, also could I just run a separate airline in the side of the pond rather than through the bottom drain, don’t like the idea of air bang in the middle of your pond

[@DazzleKoi]

Hi James, it depends where you are in the country. Its a good idea to find a local koi dealer and strike up a relationship with them if possible. I get my stuff from Tim Waddington at Quality Nishikigoi but if your ordering and having it delivered cascade koi or absolute koi are usually good. Bottom drains I know the chap who invented the spindrifter bottom drain, he has alternative aquatics, so I get them from him as I can collect myself, he's only down the road. You could just run an airline in the side of the pond but bottom drains have air domes on them as it pushes the waste in to the drain. They don't work anywhere near as efficiently if you don't have the air on top. If you put air in somewhere else you would need to put some thought in to where it goes as it is vital to create the correct flows and circulation or you will just get waste collecting on the bottom and harboring bacteria.

[@jameshayton8469]

Hi Daz, really appreciate the reply. The local koi shop put me off a air line bottom drain saying they get blocked all the time, but with your advice on the airline connected to bottom drain, which creates the waste to go into the bottom drain this makes good sense, so think I will be trying this method. I’m going to be running an eazy pod, so which airline bottom drain would you recommend. Sorry to be asking so many questions, just really want to get it right first time, also the feedback is fantastic

[@DazzleKoi]

If you can find a spindrifter I would go with that but they can run a bit expensive. If not, the other aerated bottom drains are all very similar. There is nothing much to go wrong to be honest. With the spindrifter you have a second, 1" pipe running with your main bottom drain line and this carries the air. You fit an adapter at each end so the pipe itself become filled by the air pump and hose goes from the end of the pipe to the aerated dome and from the other end to the pump. Most koi ponds have these fitted and I've never heard of one single blocked air line in 25 years mate so I honestly wouldn't worry about that 👍👍

[@joshuajones3590]

Hi daz I’ve put a 2 inch pipe in for a bottom drain pond will roughly be 4000L will this be okay?

[@joshuajones3590]

Just add I’ve used 45 degree bends and has plenty of fall

[@DazzleKoi]

Hi Joshua, you really need to match your drain and pipewrok to your filter flow. You dont say what filter you plan to use but I can't think of a filter that would filter 4000 litres properly and run on a 2" line. I would suggest going to 3" for a filter that is gravity fed from a bottom drain.

[@carollycett1329]

Good advice thank you

[@DazzleKoi]

Thanks Carol, take care 👍👍

[@chrismcerlain1664]

really interesting points there. Would you say it would be better to have the swept bends on the pipe work from the bottom drain rather than the 90 elbows ? I'm in the planning stages atm, the swept pressure bends are 3 times the price, but if its worth it, then i`ll build it in. I want to get it right 1st time .

[@DazzleKoi]

Hi Chris, its a tough call this. At face value the swept bends give less restriction and thus less reduction in total flow. They will also help with solids passing through easier (you can use two 45's as well instead of a swept bend). However, as you say they are a lot dearer so if you are nowhere near the maximum capacity of the pipe then in theory it shouldn't matter. For what its worth I have only ever used swept bends.

[@chrismcerlain1664]

@@DazzleKoi cheers mate. I think I'll go for swept ones. Only going to need 3 of them at most so...

[@iosaccoleman]

That was very helpful. I'm currently constructing a sleeper pond with a liner. Roughly 5,300 liters. Can anyone recommend a 3" bottom drain that attaches to a liner?

[@DazzleKoi]

Hi hi, I always recommend a genuine spindrifter if your budget allows. They are a bit more expensive than some but they are really good and well built to last.

[@dougiemontana4815]

Interesting, do you have a purge valve to waste on your bottom drain pipe?

[@DazzleKoi]

Hi Dougie, no, no purge valve. I have a 3 inch bottom drain and pipework which goes in to the Pod at 3 inch so no need for a valve. The line is effectively purged every time I refill the Pod after a clean.

[@dougiemontana4815]

@@DazzleKoi thanks, sorry if questions seem silly but I’m a novice, your videos are probably the most helpful out there👍

[@DazzleKoi]

Hi Dougie, no mate, not silly at all. Glad to help. Any more questions just ask 🍻🍻

[@dougiemontana4815]

@@DazzleKoi ...so for a pond of 12-1400g (final plan not in stone yet) on a 3” to easypod, how many litres p/h would be ideal? Thanks

[@DazzleKoi]

Hi Dougie, the optimum flow through the Eazy Pod is 5500 litres per hour. You are getting quite close to the limit for a Pod there though, I would consider looking at the nexus 220 , particularly if you go any bigger at all

[@tizzledexter6260]

How do you decide om design of a purge system, this is new to me and conisdering im embarking on a approximate 10k liter I'm guessing ill need a clean out on the 4 inch.

[@DazzleKoi]

Hi there, its all down to your setup and access to drainage etc. You need to be able to open up the drain to waste at the full 4" diameter, BEFORE any size reduction. So one way is to fit a T on the vertical section of pipe coming out of the ground in your filter house. Fit some horizontal 4" pipe coming off this T and then a valve. The other side of the valve then need to go to waste. So when you open up the valve the full flow comes out and the water in the pipe is pushed out at maximum velocity thus taking any muck sat on the pipe with it.

[@tizzledexter6260]

@@DazzleKoi vs an actual discharge site would something like dumping into a corrugated pipe for dispersement work?

[@DazzleKoi]

Yes mate, no reason why not. You can get away with doing it say once a week in the summer and less in winter but just be aware that there is a lot of water going to come out quickly. As long as nothing restricts the flow though it will work fine 👍 Some people dump it in to a tank or sump and then pump it to drain if the drain is far away.

[@mattjackson8439]

Hi currently building my pond and at the point of ordering my 3” bottom drain, before concreting in does the pipe work need to be layed level or with a slight gradient towards easy pod ?

[@DazzleKoi]

Hi Matt, all pipework needs to be level. All fittings are at right angles so pipe needs to go in to fittings squarely, not on an angle. The waste has to travel up a vertical section of pipe to get in to the pod anyway 👍👍

[@asterixborden-koi6881]

Thank you for putting this out I will be upgrading my pond and want to put in a bottom drain I was thinking of a 4” drain but now I’m not sure what size to put in My pond will be roughly L-9’ X W5’ X D4’ Will be buying a easypod any recommendation for what size drain please 👍

[@DazzleKoi]

Hi mate, you should go for a 3" drain for the Eazy pod. It requires 5500 litres per hour maximum so it to small for a 4" drain. You would have very slow water movement and suffer from settlement and potential bacteria issues. I use a 3" drain on my pond with a pod 👍🍻👍🍻👍

[@asterixborden-koi6881]

@@DazzleKoi thank you very much for coming back to me and your advice I have done a plan of what I’m trying to achieve if you want to have a look (Borden-Koi) if you get time 👍

[@DazzleKoi]

Hi mate, I've had a watch of your plans video 👍 Definitely a 3" drain, 4" is to big and will give you problems. For the height of the pod, around 23" but one piece of advice, its hard to get it spot on first time. There is an element of guesswork. So always air on the low side as its very easy to slide something under it to lift it up more if you need to but its often a very big job to make it lower if you sit it to high. The return to the pond can be either mid water or over the wall. Personally I like over the wall as I have a rubber elbow on the end so I can change the direction of it periodically. The return is very important to create circular flow which keeps the bottom of the pond clean and makes sure the waste ends up in the drain. I also like the extra aeration you get from the water splashing in to the pond.

[@asterixborden-koi6881]

@@DazzleKoi thank you very much Yeah I have been told to fit the pod low at first you can always raise it if needed I was looking at it the weekend and now the width will probably be more like 4 and a half to 5 foot but until I start digging I won’t know Thank you very much I will subscribe to your channel and keep you updated 👍

[@DazzleKoi]

No problem mate, yes get me up to date with how you get on and if you have any more questions just ask 🍻🍻

[@anthonyjackson4034]

Excellent video. Very informative. What diameter do you think a 4 inch bottom drain would pull. I.e how many feet around drain would be covered? I am going to build pond 20ft by 12 by 5 deep. I reckon about 6k gallons. Thanks

[@DazzleKoi]

Hi Anthony, the distance the drain pulls is predominantly determined by the height you set the dome at but they are linked because you should set the dome so that the area of the gap all around is the same as the cross sectional area of the pipe. For a pond of that size I would recommend two drains. Positioned central across the 12ft and 1/3rd and 2/3rds across the 20ft. You will keep the bottom nice and clean with those if you use aerated domes.

[@anthonyjackson4034]

Thanks for the prompt reply. I am eager to get on and dig - too much water in the ground at moment. Have you researched up pipes on 4 inch return that can bring the DOC's or foam up after the Baki showers?

[@DazzleKoi]

I haven't mate , no. I haven't heard of that. Are you talking about basically a built in protein skimmer? Sounds interesting

[@anthonyjackson4034]

@@DazzleKoi yes exactly that. 32mm pipe from 4 inch retur to pond just under about 6 inch from water level works. The velocity from shower pushes up DOC. I remember Pete Waddington from years ago - about 30 years actually. Is he still about?

[@DazzleKoi]

That sounds really interesting. I'm going to give that some thought, sounds like it could be really useful. Unfortunately Peter passed away about 2 months ago mate, his some, Tim, has Quality Nishikigoi in Warrington.

[@lukemichael7772]

Hi great video and love the channel just had a question is there anywhere that sells 3 inch sump bottom drains as can only find 4 or 2 inch online ? If not is it okay to use a 4 inch drain and fit 3 inch pipe with a reducing bush ?

[@DazzleKoi]

Hi Luke, sorry for the delay, I missed this comment some how. Absolute koi have the spindrifter in 3" which is the one I recommend koicarp.co.uk/Bottom-Drains/Spindrifter-Aerated-Bottom-Drain-p-620.html

[@benphillips9685]

Do you think I could use a 2inch bottom drain for my 3,000L pond?

[@DazzleKoi]

Hi Ben, no mate, you'll need a 3" for most filters for a pond of that size. For example an eazy pod. Its down to the filter and the flow rate you need rather than the size of the pond (although the two are indirectly linked) and 2" is too small for all but the tiniest filters but they wouldn't do your pond.

[@matthewnicholls2658]

Always great information, sorry might have missed it but what would the max flow to expect from a 4” pipe, I seem to be able to get between 15 and 18,000 lts through it comfortably before the flow is restricted, does this sound about right, all the best Matt

[@DazzleKoi]

Hi Matthew, I would expect a little more but its not a million miles off. The depth of the water and height of the filter inlet, back pressure from pipe run, bends etc all contribute to the total maximum flow you can get.

[@sontrinh1457]

Wow thanks so much for this info this really helps im ordering a eazypond with a bottom drain the pond is 3m long 130 wide and 130 high should I use a 2inch?

[@sontrinh1457]

It holds 3,903 lites

[@sontrinh1457]

And what size pomp do I need?

[@DazzleKoi]

Hi there, no you need a 3" bottom drain for an Eazy Pod and you want to flow around 5500 litres per hour through it for best results

[@DazzleKoi]

You will need a pump that gives you 5500 litres an hour flow AFTER you take in to account your head loss. It depends on your system but around 8000 litres per hour pump is probably close. If you can get a variable speed pump that is better so you can adjust it to give exactly 5500 litres 👍👍

[@sontrinh1457]

@@DazzleKoi thank u so much for your feed back i know what to do now 👌

[@gliffics1]

Just plannig my first build, looking at circa 10,000 litres. I assume from this video that a 4" bottom drain is best?

[@DazzleKoi]

Hi Ben, it depends what filter you are using but it is fairly safe to assume that with a pond that size you will need a filter that requires a bigger flow than a 3" drain can handle. Id be very surprised if you didn't need a 4" drain 👍👍

[@gliffics1]

@@DazzleKoi Thank you for your reply, I did think that 4" would be required but wanted to check. It is my first pond/build so just trying to research as much as possible, but the information out there is SO variable lol its difficult to decifer what is and isnt required/necessary

[@DazzleKoi]

Hi Ben, yeah there is a lot of conflicting advice mate. Its a minefield. Best thing is exactly what you are doing. Ask questions, watch videos, and best of all, if you can, go and see this equipment in action on a hobbyists pond. People who have lived with a filter are best placed to advise on its performance 👍

[@gliffics1]

@@DazzleKoi Yeah thats the trouble, I dont know of anybody with this sort of background/experience, although I think a family friend used to many years ago so may drop them a message and see if they still dabble lol

[@DazzleKoi]

What about koi deelers? Any close to you that you could talk to?

[@thepeoplespond]

Hi mate I’ve got a quarantine tank I’m thinking about adding a 4” bottom drain too It’s 1m x 60cm x 89cm So roughly 550 litres From watching the video, 4” is not suited right? Thanks

[@DazzleKoi]

Hi mate, yeah that's way to big to be honest. A 2" drain is probably closer to what you need but what filter and flow rate are you planning to use?

[@thepeoplespond]

@@DazzleKoi I’ve got an eazy pod i want to put onto it, gravity fed And pump using a 10000 varipump out to a smaller bakki shower above the tank

[@DazzleKoi]

Ah Ok, definitely a 3" drain then. 3" is perfect for Pod flow rates 👍👍

[@thepeoplespond]

@@DazzleKoi Thanks mate Really enjoy the videos And have Learnt a lot from you So thanks P.s when is the bakki shower content going to start Thinking of buying one but also would like to make it with your videos 👍

[@DazzleKoi]

Hi mate, the third one about the actual construction will be up on Monday 👍👍

[@iosaccoleman]

Anyone know if a 2" bottom drain is too small for a 1,400 gallon pond?

[@DazzleKoi]

Hi mate, it depends on what filter you are using but I haven't seen many, if any, that would filter that volume and require such a small flow. Gravity fed I would go 3" for something like a Pod, 2" wouldn't flow the 5500 litres or so that you need.

[@markbrady7462]

Great video once again on something we always forget. I suppose pump size is also linked to pipe diameter and length?

[@DazzleKoi]

Hi Mark, its more based on the flow you intend to pull through it so yes pump size is linked directly 👍

[@richardcoad9855]

Hi great video again I’m really enjoy them, there keeping me going through lockdown v3. could you advise the maximum area of pull for a 4” aerated bottom drain. I’m going to be building a new pond but haven’t decided what size, it’s either going to be 4 x 4 m or 5 x 3 m or maybe even 5 x 4 m with benched bottom. Would one bottom drain be enough for this size would it clear the bottom of much or should I use two, I really only wanted to use one and keep a good flow of about 18000 litres an hour. I intend to use returns on three sides of the pond which I’m hoping will put a good movement of water in the pond.

[@DazzleKoi]

Hi Richard, you are on the limit of one at 4m x 4m and if you go 5m x 3m I would definitely go with 2. You might also struggle to get 18,000 litres through one drain depending on depth, pipe length, bends etc What filtartion are you planning?

[@LauMagroTheFrenchKOInection]

Really good. Great explanation. Not easy to find 3 inch bottom drains. I will have to order. You seemed very cold. You should get one of those heated body warmer. They are amazing. Stay safe.

[@DazzleKoi]

Hi Lau, thanks, yes I was freezing 😁 A heated body warmer sounds ideal, I'll have to look in to that 👍 If you are looking for a bottom drain I recommend a Spindrifter if you can get one. They have never let me down yet.

[@LauMagroTheFrenchKOInection]

@@DazzleKoi will look into it. Just worried about installing it.. but I'll get there. Can you tell more about spin drifter vs others? May be in another video. ☺️

[@DazzleKoi]

Hi Lau, as far as I'm aware spindrifter is the original aerated bottom drain that all others have copied. It has a rubber dome that prevents water flowing back in to your air line when the pump is turned off. Its also extremely good quality and well built, I haven't heard of one failing and I used my first about 15 years ago. Its made by a company called alternative aquatics. Its a little bit more expensive than some out there but well worth the extra 👍👍

[@LauMagroTheFrenchKOInection]

@@DazzleKoi perfect. Thank you for that Darren. I will definitely look into that.

[@GottoLoveThailand]

Can I run 30,000 L in our through a 4 inch pipe thank uou

[@DazzleKoi]

Hi mate, yes you should have no problem with that flow in 4" 👍👍👍

[@GottoLoveThailand]

@@DazzleKoi Thank you

[@mirola73]

If you religiously flush your filter a few times a week purging the pipe, you shouldn't have any serious issues with settlement. Maybe when it's hot in summer once a year dive in and put a brush through it, then purge it. Done.

[@electoplater]

bottom drain great for breading bug problems like flukes

[@DazzleKoi]

Hi Humphrey, you are right in that a bottom drain is perfect for breeding bugs but its bacteria that breeds in there such aeromonas bacteria, not flukes. Flukes are a parasite which means they live off the creature they are on and so they wouldn't survive in pipework, they need to be on a fish to survive.

[@Chequr_Prostate]

If I was a koi and aquatics business I’d sell pond plans, based on 3 or 4 standard sizes. Plus a kit list. Or If the customer was going to buy the kit from my business I’d give them the plans for free.

[@DazzleKoi]

Hi Andy, that's a great idea mate. I might pinch it 😁😁

[@Chequr_Prostate]

Feel free, 👍 And thanks for all your work, I love your content, and it’s helped a newcomer like me so much. Thanks again.

[@DazzleKoi]

Hi Andy, I've thought about this a lot since you came up with the idea. I think it could be good to be able to offer plans, material lists and costs, access to instruction videos, phone/email support etc etc etc in a package with a one off purchase fee. Different sized ponds, different filter options, there is definitely something in this.

[@jasonm2969]

You look cold in this vid but thanks for the info.

[@DazzleKoi]

haha, yes I didn't even realise while I was filming but when I edited it I was shivering. Bring on Spring 👍

[@bonganimatjeke3455]

@@DazzleKoi hi there. Firstly let me thank you for your educational videos, very articulate. I have question i would like your advice. Im just about to complete a raised pond its very big as i intend to have atleast 2 or 3 koi and the rest goldfish. I dont have bottom drain so im deciding to put retro bottom drain. My pond will run pressurised filter 5000. However, would you advice/ recommend i put a 2nd filter(diy) that will connect to the bottom drain and once filtered the water back to the pond? My reason for thinking of having a second filter is that i see alot of ppl saying that pressurised filter don't always work as they should..my pond is around 3000gallons. Thanks for taking your time to read & reply.

[@DazzleKoi]

Hi there mate. I don't know which pressure filter you have but in general they aren't the best for a bigger koi pond like yours. Just with the limited info I have I would recommend you think about adding something bigger and better. The one you have now might be ok initially with only 3 koi but it wont be long before they grow and/or you add more koi and your pressure filter probably wont be good enough then. I would say get it all up and running and see how you go and do some research in to a better filter while you gain some experience of the one you have now 🍻🍻👍👍

[@bonganimatjeke3455]

@@DazzleKoi thanks for the advice Much appreciated

[@damonstuchbury7841]

COLD IN THE NORTHWEST EH

[@DazzleKoi]

Bloody freezing 😁 To be honest I think I'm just getting old 😒

[@electoplater]

NO BIGGER than 3 inch sacramento koi