GH for Koi keepers (Water Hardness)

GH or General Hardness is one of the less tested parameters in the Koi pond system as it is generally within an acceptable range when left to its own devices. It does however have a preferred range and it is important that you stay within that range.
In this video I talk about what GH is, how it varies depending on your source water, what range you should aim to stay within, hard water & soft water, and what effect it has on your koi amongst other things.
Check out my website at www.dazzlekoi.com/
If you enjoy the video and find it useful please hit the like button and don't forget to subscribe to my channel here rb.gy/dp57so for more content on this wonderful hobby.
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[@simoncalveley5582]

First look on you channel. Really informative and will be tuning in. Thanks for all the info. Answered a lot of questions 👍👍

[@DazzleKoi]

Cheers Simon, I appreciate you taking time to feedback mate 🍻🍻🍻

[@nwcaymans]

Hi Daz- I'm a new subscriber and I really liked your discussion of GH. Our water hear in Washington state, USA is very soft. Since I strive to keep the KH and pH in the proper range, it only seems logical that I try to do the same w GH. You are the first source to provide any real clarity on this topic. Thanks much. I look forward to watching your other shows and thanks for sharing your knowledge.

[@DazzleKoi]

Hi Rick and welcome 👍👍 Great to here you found it useful Sir 🍻🍻

[@peterkoczkowski5000]

Hi Daz brilliant info once again a bit over my head but need to watch again and again so it's sink in can't wait to see your new koi in the pond keep up the good work 👍👍🐟🐟

[@DazzleKoi]

Thanks Peter, same here, it was hard having to wait another week but I know he's right and its good that he cares so I cant complain really 🍻🍻

[@sandypollard562]

Never boring 👍 excellent explanations and easy to understand tyvm

[@DazzleKoi]

Thanks very much, I really appreciate that 🥂👍🥂👍🥂

[@SaquibChowdhury]

What an amazing pond you really helped me a lot with everything thank you soo much my pond is pump fed and your videos are really helpful thank you soo much Daz

[@DazzleKoi]

Thanks mate, I really appreciate that. Just been watching a couple of your videos. Not a fan of fortnite, I play mostly COD, but fun to watch you kicking butt 👍👍👍

[@Tom_Prendiville]

Daz I'm so glad you added in the myth of mud ponds being magical when in reality they are indeed completely devoid of minerals. Very informative 👏🏼 Thanks for sharing matey 👍🏼

[@DazzleKoi]

Thanks for your feedback Tom, much appreciated 👍🍻👍🍻👍

[@RosieKuhnPhD]

This was really interesting. The topic of shimmy was helpful. That’s a great indication that my water in more on the hard side, as shimmy is showing up on one particular koi! I think its more helpful to know these indicators vs. test kits. How it makes a difference in the fish specifically is more fascinating! Thank you again! I’m on the West Coast of the US in Washington. Just letting you know you have a far reach!!

[@DazzleKoi]

Thank you very much Dr Rosie for your kind words. It still amazes me to think I can film myself on my phone and someone thousands of miles away can watch it. Even more alien to me is the fact that they would actually want to watch it 😁😁😁 Thanks again 🥂

[@tomtomrst20]

Another great video 👍

[@DazzleKoi]

Thanks again mate 🍺🍻🍻🍺

[@baitking1]

Hi Daz thanks for this video really helps me great video as always

[@DazzleKoi]

Cheers pal 🍻🍻

[@andrewwestwood485]

Another informative videos. 👌 j currently add mediclay once a week in my pond so will be really interested in your upcoming video on this...

[@DazzleKoi]

Thanks Andrew, I'll get cracking on it 🍻👍🍻

[@just4koi143]

The fish behind are dazzling matey, shower looks great blends in well with the concrete slab fence, always picking up plenty info from your channel, thanks matey keep safe 👍🏻

[@DazzleKoi]

Thanks mate, I see you have been busy to, good stuff. Almost at 1000 subs to 👍🍻👍🍻👍

[@just4koi143]

@@DazzleKoi thanks matey, almost 1000🙈🤣👍🏻keep safe

[@iainbusbridge9585]

Very interesting. I like the koi masters advantage as it does improve my water clarity. I have also just got some kusuri super c to try. I have often wondered if running RO water into the pond would be better then I could control the gh with the amount of mineral I put into the pond.

[@DazzleKoi]

Hi Iain, I think it largely depends on the source water as the vast majority has all the minerals and trace elements your koi will ever need but there are some supplies that would benefit from additional intervention. I'm going to do a video specifically on RO as several people have asked about it so watch this space 👍

[@richardbrunton2068]

Great info as per.cheers daz👍

[@DazzleKoi]

Thanks Richard, all the best 👍👍🥂🥂

[@carollycett1329]

Great video Daz always good information given 🙏🐟🙏

[@DazzleKoi]

Thank you Carol 👍👍

[@terencegander8342]

Great video again mate 👍

[@DazzleKoi]

Cheers Terence, thanks very much 🍻🍻

[@marekskoipond9083]

Interesting answer you gave to earlier comment about feeding and water heating up lowering ph, I've just fitted my ashp about 2 weeks ago and as a consequence am feeding, as it happens done water testing today and ph was 6 and kh not even registering on my idip test meter, last week had ph of 7.6 and kh on the idip 100 ppm, can only think filter bacteria is stripping pond of kh, just put in 450g of bicarb, but think I'll order some oyster shells, hopefully to keep ph/kh more stable long term.

[@DazzleKoi]

Hi Marek, sounds like you have it under control there. Its a pain when your source water is lacking back once you get in to a routine with the bi carb you'll be fine 👍👍

[@richd-koi6974]

Another good update mate. I've learned to just go with it and not over worry about my water. Ph 8 kh 3-5 which i buffer with bicarb weekly. Never tested GH.

[@DazzleKoi]

Hi mate, I'm with you on that. I like to leave well alone and not over complicate things as much as possible. Some tap water can be pretty poor though and sometimes there is no choice but I'm lucky in that mine is really good at the moment 👍👍👍

[@richd-koi6974]

@@DazzleKoi At least there's some perks to living up north 🤣👍🐟

[@DazzleKoi]

haha , yeah, every cloud has a silver lining 😁😁

[@anthonywatkins2783]

Another great informative video 👍

[@DazzleKoi]

Thanks Anthony 👍👍👍

[@garysmith5966]

Thanks Daz. I live in a hard water area. Now I know why I get shimmy’s on the fish. Another great video.

[@DazzleKoi]

Thanks Gary, I used to have the same issue myself and it drove me mad. I stopped buying kohaku in the end. But I moved across town and now its much softer and my pH is lower. Its so much better 🍻👍🍻

[@garysmith5966]

@@DazzleKoi likes like I’ve got to get the house up for sale😀.

[@DazzleKoi]

We'll probably move soon but I'm insisting on staying in the same area 😁😁

[@andycox3862]

Very interesting matey 👍👍👍 thanks 😁

[@DazzleKoi]

Thanks Andrew 👍🍻👍🍻

[@KoiRun50]

You’re a textbook of knowledge and better👍 .

[@DazzleKoi]

Cheers mate, I really appreciate that 🍻👍🍻

[@asterixborden-koi6881]

Thank you for sharing Here in Kent very Chalky interesting video 👍

[@DazzleKoi]

Cheers mate, thanks for commenting bud 👍🍻👍🍻👍

[@tonyscerri6039]

Great videos Daz, all very well explained, be nice if you could explain conductivity ( TDS) thx, keep up the good work.

[@DazzleKoi]

Cheers Tony, much appreciated. Yes I'll definitely add TDS etc to my list of videos to make 🍻🍻🍻

[@LauMagroTheFrenchKOInection]

Fantastic as always. Had to watch some bits twice as usual to take it in. Our pH is high here in Hampshire 8.5 tap and pond. I am looking into bringing it down a bit with the Colombo Minus. One thing I was going to ask you, I have done a bit of research on Phosphate and the benefit to be around the zero mark to 'stop' (if this is possible) the blanket weed growth. I have done some testing, I was at 1 of phosphate, kept it at zero (from Colombo test kit) and first time I have no blanket weed at all. What are your thoughts? Are you up to do a video on that?

[@DazzleKoi]

Hi Lau, I tend to lump nitrate and phosphate together as they can both provide nutrients for the dreaded weed. I will certainly do a video on it though, i've added it to the list 👍👍 PS: I honestly wouldn't worry about pH 8.5, its fine. It will come down a but anyway soon when the temps warm up and you start feeding more.

[@LauMagroTheFrenchKOInection]

@@DazzleKoi great for your advice on the pH. Thank you Darren. And thank you for adding the phosphate on your list 😁

[@Harrycapon1026]

Great video as usual. What is your view on using pp as a medication in your pond. Do you use it? Harry

[@DazzleKoi]

Hi Harry, I have never had the need to use PP but certainly if I find parasites that PP will kill I will look at it. It is quite harsh so I know there is often a more koi friendly alternative but I would look in to it as and when. I've been lucky in that I've only had one bout of flukes in 25 years so I'm not very knowledgeable when it comes to treatments.

[@ItsWhatIDo]

Just a thought that sprang to mind. What effect do RO systems have on water hardness? In my mind they would reduce GH and quite likely KH as well. I haven't got an RO system so it's purely an academic question. In regards to clay I use Koi Master advantage which isn't strictly a clay. I don't tend to use it as regular as I should according to the instructions but it does have an effect on the water.

[@DazzleKoi]

High, mate, I just said above, I think I'll do a test of koi masters after I've tried the mediclay. I don't know to much about it if I'm honest. RO I have been asked to make a video on by a few people now so that's on my list, hopefully I'll get to it soon 👍🍻👍

[@MrSmithy63]

Hi mate , been revisiting some of these videos as recently had some issues with water. How did you the clay work out ?

[@DazzleKoi]

Hi mate, I think you may be referring to a test I planned to do on the effects of clay?? If so, I didn't see any difference at all. I gave up in the end as it felt like the most boring video ever 😁😁

[@northernkoikeeper512]

Hi Daz. Another very interesting video. Thanks. In a future video(s) could you address the subjects of the advantages and disadvantages of adding Bicarbonate of Soda to the water and also Salt. Thanks.

[@DazzleKoi]

Hi mate, the bi-carb I've covered more or less in the pH and KH videos. I would never put salt in my pond, I'd only use as a short term bath if I had certain ailments, but I could certainly add it to my video list 👍👍 If you've not seen the pH/KH ones have a watch and if you think I could do more detail on bi-carb specifically , let me know

[@dalboy247]

Hi Dazz. Another great video mate. Can you do one on TDS and RO water why some use and most please say away from it? My tds out of the tap and filter is about 350 to 400 what seem high to me? Thanks and keep them coming mate. 😜

[@DazzleKoi]

Cheers Darren, yes that is a high TDS. Not the end of the world but high. I will definitely add RO and TDS to my list of videos 👍👍👍

[@alexw9177]

Hi Daz, your Bakki shower construction vid were good, any chance you could do one on a moving bed?

[@DazzleKoi]

Hi Alex, yes definitely. I've added it to the list mate 👍👍👍👍

[@paulholt8311]

Hi Dazz you certainly help to explain the ins and out of water testing and was interesting that it had a effect on the colours, would you say that the colour enhancing food helps to maintain the colours?

[@DazzleKoi]

Hi Paul, my understanding of colour enhancing food is that it is just a temporary thing and that if you come off it they will fade back to their natural state. I don't believe they do anything to change what genetics and mother nature gave the koi. People who show their koi only use colour food in the run up to a show to give that temporary boost.

[@paulholt8311]

@@DazzleKoi makes sense 👍

[@paulholt8311]

Hi Dazz I use a product from envii called pond equaliser it helps to buffer the water pH kh GH have you ever used it ?

[@DazzleKoi]

Hi Paul, I haven't , no. I've just googled it and to be honest I cant find much info on the chemicals it contains so its hard to say what it does. It claims to either raise or lower your pH which simply means it has a pH of 8. So if you put it in a pond of pH 8.5 it will reduce the pH and if you put it in a pond of 7.5 pH it will increase the pH. If it buffers GH then it will contain minerals similar to clay and I assume some bi-carb to add carbonates for the kh buffering. I'm lucky in that all those parameters are great straight out of the tap so I don't need to add anything like that but it sounds as though it would be useful if you suffer low kh. Do you see any benefit from it?

[@dollyburn9203]

Hi there amazing video I have a question which I really need help with my pond is pump fed sometimes I lose pond water not sure if it’s sunlight or so I’m running an eazy pod any top up ideas do you have to save me on water bills from constantly getting the hose

[@DazzleKoi]

Hi there and thank you very much 🍻 I guess it comes down to where the water is going. Here in the UK we don't lose water through evaporation, at least not enough to notice and the rain more than makes up for it. I have heard of people in warmer countries losing water through evaporation though so its not impossible. I think you need to investigate where it is being lost. Is it a liner or a fibreglass pond (or concrete)?

[@dollyburn9203]

@@DazzleKoi I’m looking in getting the tempest filter can that be used in pump feds with my eazy pod

[@DazzleKoi]

Hi there, yes you can use the Tempest if you are pump fed. The Tempest would go before the eazy pod 👍👍

[@badenwright6375]

Very interesting mate.I did my testing today and have Ph of 8 Kh of 3 and Gh of 4.I have only recently set up a trickle in/out and have since struggled getting the Kh up with a mix of bicarb and the nt labels buffer.i test weekly and it’ll drop 1degree.adding approx 10 teaspoons will lift it back up 1.tested the Kh from the tap and its non existent.I would have thought the Ph would be lower?should I be looking at buffering the Gh?cheers Darren

[@DazzleKoi]

Hi Baden, you will need to keep buffering the kh (I'd stick to the bi-carb as its much cheaper) but the GH is fine. Its exactly where you want it in fact. Your pH will come down a bit when you start feeding heavier and the water warms up but 8 is fine. It looks like you will need to add an amount of bi-carb every week unfortunately. Trial and error to determine exactly how much you need to add.

[@badenwright6375]

@@DazzleKoi cheers mate your help is appreciated

[@DazzleKoi]

No problem , let me know how you get on 👍👍

[@Chequr_Prostate]

I have often wondered whether there is a health issue if you live in hard water areas. I was in China and they had carp in the rice fields, but we were told this was just as a food supplement for the farmers.

[@DazzleKoi]

Hi Andy, yeah I dont think they care to much about their wellbeing when they intend eating them 😒 I dont think its so much a health issue but they definitely dont grow as well or become as colourful in hard water. It does make the whole process of keeping water slightly more challenging to. The neutral, pH 7 in Japanese water is perfect but we tend to be higher over here in the UK. Closer to 8 or even 8.5 pH in my neck of the woods.

[@mattpettitt3204]

Hi Daz. I was looking at using Mediclay but have gone for koi masters advantage instead. Don't think that is a clay format. Can you give your thoughts on that please? Bought it but not added yet. Thanks Matt.

[@DazzleKoi]

Hi Matt, I do know koi masters is very well liked in the koi hobby and people swear by its results but I have no experience of it myself. As you say, its not specifically a clay but beyond that I don't know any more. I'm going to test the mediclay I have here soon so maybe I can do the same with koi masters after that 👍👍🍻🍻👍👍

[@mattpettitt3204]

@@DazzleKoi thanks. Will be hard for me to say as my pond is pretty new. Always had ponds but this is my 1st specific koi pond. Love the videos really informative 👍👍

[@DazzleKoi]

Thanks Matt, let me know how you get on with it 👍🍻👍

[@JMacFlyFishing]

Well done Daz, another very informative vlog. 1 quick question, I rightly or wrongly thought that GH would determine how a pond would mature? Many thanks, JMAC 😎🐟👍🏼

[@DazzleKoi]

Hi mate, I haven't heard that and I don't really see how GH would have any bearing to be honest. Its easier to mature a pond if you have low pH because the ammonia is less toxic so you can allow higher levels to build up but other than that I cant think of any benefit to the maturation process from having harder or softer water.

[@JMacFlyFishing]

@@DazzleKoi thanks for the reply 👍 keep up the great work 👏.

[@Mikemkp]

Looking good daz fancy a trip to the Wirral to put one of your overflow systems in 😂

[@DazzleKoi]

I wish I had time mate, I'd love to. Maybe I can come and do a video on your setup some day and sort the overflow at the same time 😁

[@Mikemkp]

@@DazzleKoi no worries Darren that would be great ordered 15 kg of the Kano mate got the discount cheers buddy 😀

[@DazzleKoi]

Nice one. I believe there is quite a wait for the media now. Its turned out to be very popular 😁😁

[@Mikemkp]

@@DazzleKoi yes mate they said about 3-4 weeks 👍🏻

[@chrisshadwick5833]

How would you reduce Gh as I’m in Yorkshire and my readings are very high at 17dh what would you recommend to bring it down

[@DazzleKoi]

Hi mate, I've heard of much higher Gh (25) and that didn't cause any problems so I would suggest its fine and best left alone. I think you would need to look in to an RO system to get it lower. This would strip out KH and GH and then you would need to add back in some carbonate to bring the KH back up (sodium bicar or similar). Your water will be good for sumi but will encourage shimmi in white based fish such as kohaku etc. I would honestly just leave it alone unless you are spending many thousands on koi

[@chrisshadwick5833]

@@DazzleKoi thanks for the reply and thank you for your info 👍

[@andrewmason2879]

I did not no that adding clay pushes your PH up. Not a good idea if you live in a hard water area then. Interesting to no that the mud ponds in Japan don’t have any nutrients in them. I always thought they did. Do you not put anything in your water at all? You amaze me how much you no especially when you start talking about the chemistry involved in it all. I need to read more 😀 mate. Thanks for sharing your knowledge with us all. 👍

[@DazzleKoi]

Thanks very much Andrew. No I don't add anything to my water. I have no chloramines so I'm happy to let the chlorine from the trickle in gas off naturally. pH and GH etc are fine out of the tap. The only thing I add is fresh water. I try not to overcomplicate things as from experience it doesn't add any benefit and just adds to the stress thus taking away from the enjoyment of the hobby. 🍻🍻

[@lewisjones9963]

Hi mate any tips on low GH and kh my tap water is low to start with ph seems stable at 7.5 8 thanks

[@DazzleKoi]

Hi Lewis, I wouldn't worry to much about GH being low, there will be more than enough minerals for your koi and if not they get it from koi food too. Low KH is more problematic as it can lead to a pH crash. When you say its low, what is the reading?

[@lewisjones9963]

@@DazzleKoi hi thanks for getting back it’s was reading a 1 DH but iv started to use bicarbonate of soda this morning and re tested just now and it reading a 4DH now has my tap water is very soft iv been advised to use bicarbonate at 100 grams per 1000gal per day until I reach the correct level but what realy is the correct level

[@lewisjones9963]

@@DazzleKoi ammonia is 0 Nitrite is 0 Nitrate very little PH seems to be swing up and down 7.5 to 8 but when up 8 after the bicarbonate this afternoon Phosphate this is very little KH was 1DH now after bicarbonate it 4Dh and GH is 4DH will test again in the morning

[@DazzleKoi]

Hi mate, 4DH for KH is perfect. That will give you a nice safe buffer against pH crashes. If you can add a little bicarb, say each week, to keep it at 4 that would be ideal. You are just adding enough bicarb now to replace in carbonates which are used up by your system. Filter bacteria etc will use small amounts each day.

[@lewisjones9963]

@@DazzleKoi excellent thanks very much hopefully fish will be happier now they was flashing 2 days ago that seems to have stopped but fish are very spooked when I’m near pond staying around the bottom but hopefully this will change Now .but just watched your new video as well on filter change I will definitely be giving it ago has I cleaned my filter yday for first time in 2 weeks and it was rotten thanks again

[@GrahamTaylor123]

Interesting about the colours with hard and soft water. I live in hard water area and have had a few fish like the red. Always thought it was maybe down to generic but maybe not.

[@DazzleKoi]

Hi Graham, when I lived in a hard water area I was plagued with shimmi on kohaku. So much so I had to stop buying them in the end and stick to sanke, showa and shiro.

[@robertdowning2033]

Are you going to be upgrading your koi pond soon making it much bigger

[@DazzleKoi]

Hi Robert, I move house fairly regularly so its not cost effective for me to build big ponds. I just have to make do with a smaller one until we settle down in one place.

[@robertdowning2033]

@@DazzleKoi what’s the most expensive koi in the pond

[@DazzleKoi]

Hi Robert, they are not expensive fish, around £100 for the Showa is the dearest.

[@robertdowning2033]

@@DazzleKoi would you ever spend thousands on a fish

[@DazzleKoi]

I have in the past but I wouldn't any more. I don't have thousands to spend anymore but its too stressful anyway.

[@georgecromar4094]

How do you know all this stuff Mr Dazzle?🤓

[@DazzleKoi]

Hi George, I think I read to much and spend to much time in my filter shed. I probably need to get out more if the truth be told 😁😁😁

[@garyneo2259]

hi darren my PH 7.2. AMMONIA 0, NITRITE 0. KH 7 DROPS.NITRATE 0 GH 0 DO I HAVE ANY PROBLEMS REGARDS GARY

[@DazzleKoi]

Hi Gary, that's a strange set of numbers but not impossible. I would just check that GH again and maybe check the GH from your tap to. If its higher in the tap you need to do more water changes or set up a trickle in / out of you don't have one already. You could also look at using a clay to boost the GH

[@garyneo2259]

hi m8 those results was taken this afternoon just redone the tests all the same except the OH which is now 6.9 and no nitrate in the tap water sorry to be a pain m8 regards gary

[@garyneo2259]

PH 6.9

[@DazzleKoi]

Hhmmm, its stange that mate. This is probably a daft question but you are definitely not mixing the GH and KH up? It is odd that you have such high KH (7) but your pH is so low. If those numbers are correct I would definitely get hold of a clay such as mediclay or similar and add the recommended dose. Then retest after a couple of hours and let me know what you get. I would also recommend just getting some bi carb on hand just in case. The pH suggests you should add bi carb but the KH suggests you have a good buffer. I never trust test kits as it can get you in trouble if they are wrong so cover all bases.

[@garyneo2259]

hi m8 been to my local koi dealer he did my water test PH.7.2 KH.7 DROPS NITRITE.0 NITRATE 0 AMONIA 0 GH.0 SO BOUGHT SOME GH BUFFER 2KG HALF TODAY HALF TOMORROW WILL LET YOU KNOW HOW I GO ON THANKS M8 REGARDS GARY

[@sandypollard562]

Look at you with shower running 👍 show off 🤣 just joking thankyou for advice really appreciate it 👍

[@DazzleKoi]

I know right!! It will be even better when I get round to cladding it 😁😁

[@wendyhughes3537]

I found it interesting about how hard and soft water will effect the colors on koi. You mentioned shimmies on red koi from hard water. Does the same thing happen to black koi getting red spots with soft water?

[@DazzleKoi]

Hi Wendy, no , that doesn't happen. I presume that is because black is actually a skin colour (showa has black skin with white and red, sanke has white skin with black and red) rather than just a pattern colour.

[@andyfindlay3815]

Hyper.interesting

[@DazzleKoi]

Cheers Andy 🍻🍻🍻