How to maintain GH & KH

How to maintain GH & KH
In todays video we discuss how to maintain GH & KH in your aquarium.
If you are new to fishkeeping you may want to watch my GH KH & pH Beginners Guide video, here is the link: • GH KH and pH | Beginne...
Maintaining GH & KH in your aquarium is very important, but it isn't something that you needless need to pressure yourself with, if you understand your water parameters from your tap, or alternatively use RO/DI to create the right environment for your little fishy friends.
General Hardness and Carbonate Hardness are very confusing when you first start out in the hobby, and I hope that my videos will help simplify the chemistry that you will need to understand so that you can successfully keep your fish for many years.
If you have any questions, please feel free to leave a comment and I will get back to you.
Happy fish keeping!
GH/Water Hardness Table:
dGH (Degrees of General Hardness) | PPM (Parts Per Million)
0 - 4 dGH | 0-71 PPM = Very Soft
4 - 8 dGH | 71 - 142 PPM = Soft
8 - 12 dGH | 142 - 214 PPM = Moderately Hard
12 - 18 dGH | 214 - 321 PPM = Hard
18 - 20+ dGH | 321 - 357+ PPM = Very Hard
Typical GH levels for Aquarium Fish:
dGH (Degrees of General Hardness) | PPM (Parts Per Million)
Freshwater Aquarium: 4-12 dGH (71-214 PPM)
Discus or Planted Aquariums: 3-8 dGH (54-142 PPM)
African Cichlid Aquariums: 12-20 dGH (214-357 PPM)
Shrimp Aquariums: 4-8 dGH (71-142 PPM)
Typical KH levels for Aquarium Fish:
dKH (Degrees of Carbonate Hardness) | PPM (Parts Per Million)
Freshwater Aquarium: 4-10 dKH (71-178 PPM)
Discus or Planted Aquariums: 3-8 dKH (54-142 PPM)
African Cichlid Aquariums: 10-18 dKH (178-330 PPM)
Shrimp Aquariums: 3-6 dKH (53-107 PPM)
Saltwater Aquarium: 8-12 dKH (142-214 PPM)
Typical pH levels for Aquarium Fish:
Freshwater Aquarium: 6.5 - 7.5
Saltwater Aquarium: 8.0 - 8.4
If you want to keep fish that are not suited to your tap water, I recommend investing in an RO/DI (Reverse Osmosis de-ionised) unit and mixing the RO water to the right levels. I use two RO/DI units, made by Vyair and Osmotics UK, below are some links to their websites:
Vyair - www.vyair.com/home
Osmotics UK - www.osmotics.co.uk/
API Freshwater Master Test Kit: www.amazon.co.uk/API-Freshwat...
API GH & KH Test Kit: www.amazon.co.uk/API-Freshwat...
Red Sea Marine Care Multi Test Kit: www.amazon.co.uk/Red-Sea-mari...
Follow me on instagram: / bigfishlittlefish_aqua...
Support the channel by purchasing merchandise: teespring.com/stores/big-fish...
#waterhardness #fishtanks #bigfishlittlefishaquatics #GH #KH #GH&KH
0:00 Intro
0:22 GH
3:15 KH

[@VinnysAquatics]

Good information my friend 👍

[@BigFishLittleFishAquatics]

Thank you Vinny!

[@martyborst5645]

Thanks!

[@BigFishLittleFishAquatics]

Welcome!

[@Mukis_Aquatic]

Nice video bro

[@BigFishLittleFishAquatics]

Thanks

[@jojocool555]

Some optimum numbers would be good, Great info.

[@BigFishLittleFishAquatics]

All in the video description and my website my friend :)

[@nathanieljthompson]

Hi I have a 140L tank that I've been using tap water on. I live in London so the water is pretty hard here. I bought an RO/DI unit and have been mixing a 50/50 ration with the RO water. I still add a tiny bit of Seachem Prime just to be safe. I've been doing this because I thought it would help with some persistent algae issues. Generally my GH and KH have been fine with tap water. GH: 8-12 and KH 6-10. I have a lot of driftwood and sometimes drop in an almond leaf. I'm in two minds really because mixing the waters allows me to get a good decent temp before going into the aquarium. But I haven't committed to RO completely due to that I need to buy a pump since my water pressure is on a minimal of 2 bars. But also I can't seem to find a decent GH & KH reminimisation power. I know I could use Seachem equilibrium but that only for GH, I could use soda powder for KH but how much to increase it to the number I want. I used a massive bucket and pump for clean water changes, so you can see why I may want to just stay with tap water, since I can use a hose from the sink. Although my tap water does contain 40mg/l nitrates.

[@BigFishLittleFishAquatics]

Have you had a look at NT Labs KH up? Is a good product for KH stabilisation with RO. I find for planted aquariums and your GH, Equilibrium is one of the best products on the market :) - Also, if you are cutting your tap with 50/50 RO, you'll probably find your levels are where you want... apart from the Nitrates, I use Pure RO specifically due to my Nitrates being too high.

[@lovelybones6891]

Tested today was in danger zone ... always something help

[@BigFishLittleFishAquatics]

Oh no! never fun being in the danger zone! remember always make changes in small and slow steps :)

[@stephanyacevedo12]

I have 4 goldfish, 1 pleco, and 1 loach. I noticed my two adult goldfish were acting a bit apathetic, and that was enough to concern me. I used a testing strip to test the water in the tank and my GH levels were in the danger zone. My nitrate levels are also pretty high, but I was wondering if a water change is enough to stabilize the levels?

[@BigFishLittleFishAquatics]

It will depend on what your source water parameters are, you will find that a 20-30% water change twice a week for the next few weeks will get you back where you want to be (assuming the water that you are using has a good level of GH and low level of Nitrates :) - feel free to share and I will try my best to advise what I would do.

[@devinrunyan]

I have a paludarium with only about 10 gallons of water and I'm struggling to maintain a Gh higher than 2, that's with adding a full cap size amount of Seachem replenish to it every single day. Yes, my water is exclusively RO water (my tap water is roughly 1 Gh so not like that would even help by much), but I'm completely dumbfounded as to how my Gh refuses to rise. It doesn't make sense to me. It's a planted tank with no debris such as leaves that could add tannins to lower the Gh. I'm using LECA in the false bottom below the ground and in the water area it's just sand. I've added bits of coral into the filter area but still, little to no change. It's almost like something is eating up Gh but I have absolutely no clue as to what. Thoughts?

[@BigFishLittleFishAquatics]

Hey, what are you using to maintain your pH? Carbonate Hardness (KH), Phosphates? What buffer solution are you using as some of these precipitate GH minerals.

[@lonerider7177]

I have nano cherry shrimp aquarium and I'm using ro water. my shrimps are dying due to lack of dissolved minerals , kh and gh... And I don't have any test kit to measure kh and gh. Can I use partial ro & dechlorinated tap water to increase my aquarium GH and kh?

[@BigFishLittleFishAquatics]

Hello, Here is a link to a video I have covered re. remineralisation of RO water: kzbin.info/www/bejne/gnmkn6eGYtKlZ5I Short answer is, yes you can... you may find the video useful to help any understanding :)

[@Vivian-uu8hc]

i’m not fully sure what to do with my tanks, my water levels are 8.0 PH, 180 KH, and 0 GH. I don’t know how to lower the PH and KH while also increasing my GH

[@BigFishLittleFishAquatics]

Hello, The best bet for reducing KH from your source water is to mix with RO/DI water or Distilled Water, if for example you mixed your source with 50% RO/DI or distilled, you'd end up with 90ppm or 5dKH. Peat moss is another option that some aquarists use to reduce KH, however you have quite high levels so would not be anywhere near as effective as RO/DI or distilled water. It is very odd for you to have 0 GH with such high KH being present, so makes your typical challenge difficult, but say you wanted to increase your GH, but not alter your KH or pH, then I would suggest finding calcium & magnesium additives, I use Seachem Equilibrium (planted aquariums) or Seachem Replenish (Non-Planted) - there are many other brands available on the market. The problem with Crushed Coral is it will also release carbonates, that add to your KH levels, and with such a high buffering capacity in your source water, it would take time for the acids to react with the crushed coral. Again all this is entirely dependant on the fish/animals in your aquarium, as some fish love high pH, so by simply adding some GH minerals to raise your total hardness you could easily keep African Cichlids, for example. Feel free to check out my website, where I talk about GH, KH & pH www.bigfishlittlefishaquatics.co.uk/gh-kh-ph

[@lovisahakansson7832]

Thank you for this information! 🤗 Is it possible to raise the GH and KH without raising the PH? I have used crushed coral so far (to stop my plants from melting) but it is raising my PH too which I don't think my fish appreciate. Will the seachem equilibrium work in my case? Thank you!!❤

[@BigFishLittleFishAquatics]

Hello Lovisa Hakansson, It is possible to raise your GH without affecting your PH, using items such as seachem equilibrium will do that for you. You will need a level of KH in your aquarium to act as your buffering capacity, depending on the fish you have they will usually tolerate anywhere between 4-10 dKH (71 - 178 ppm), if you increase KH, this will generally raise your PH level. I can try to help further if you wouldn't mind sharing what fish you have and the water parameters you have in your aquarium & the source (tap water etc.), and what & why you are aiming to achieve.

[@lovisahakansson7832]

@@BigFishLittleFishAquatics Thank you for your willingness to help me!

[@BigFishLittleFishAquatics]

Its sounds like your tap water has put you in a tricky situation, low KH levels but relatively neutral PH! This makes what you are trying to achieve with crushed coral difficult. As you raise your KH with crushed coral a typical side effect will raise your PH, and if you are already at the sweet spot around 7-7.5 it will unfortunately rise. Before doing anything else, I would suggest filling up a small bucket with some tap water, add an air stone and leave overnight. Come back the next day and test your taps GH, KH & PH - this will give you a good understanding of what you are dealing with and how you will need to maintain the aquarium going forwards. Assuming that your tap water is as you mention 'before' 0-1dGH, 1.5dKH & PH 7.5, I would recommend using seachem equilibrium to raise your GH to 4-5dGH (instructions of how you do this is on the bottles and their website... I also have a video using these products with their digital spoon (with RO water)). And then also using seachem alkaline & acid buffers, these will allow you to raise your KH to 4-5dKH, whilst buffering your alkalinity back down to your target PH of 7. When using buffers, go slow, add your changes in-line with your water changes to slowly increase your parameters, if you do it too quick it will likely shock your fish. Now, using any form of water altering technique opens you up to an element of risk... ideally using just your tap water without any buffers would be great, if after testing your tap water you notice that the GH & KH.. and subsequently PH levels are within your desired appetite of 4-8dGH, 4-8dKH & PH 6.5 - 7.5, it may be that you just need to increase your water change volumes or frequency to bring your aquarium back into balance. My other recommendation would be to use RO/DI water and re-mineralise to your specific requirements, this is more of an investment however as you would need to buy the water from a local fish shop, or buy your own RO/DI unit (which can be expensive). As I mentioned though, test your tap first and go from there... if you have any questions, let me know. Good luck & happy fish keeping!

[@lovisahakansson7832]

@@BigFishLittleFishAquatics All right! I will start to work with just a bucket of water to see what can be achieved. Out of curiosity, in what way does an air stone affect the water parameters? :) It´s a bummer that my water seems a bit tricky. It is drinkable straight from the tap but I will do my best to make sure it is not only optimal for me but for my fish and plants too. This was incredibly helpful once again and I am so thankful that you took your time to write all of this! I will come back and let you know how it went! Much love from Sweden!

[@BigFishLittleFishAquatics]

No problem at all, happy to help where I can! The purpose for aerating your tap water overnight is due to most sources of tap water having a high excess of CO2, which can cause your PH to seem lower, by putting an air stone in and leaving over night this will perform gaseous exchange and show you what level your PH actually is... if it was originally high with CO2. (test before and after to see if it does change) - its just one trick to make sure you are getting accurate readings. Definitely, let me know how you get on! Good luck!

[@meganmiller1612]

New fish keeper here! my pH is good it is 6.8 but I got low kh is 40ppm on my test strip witch it said it is low. Is that to low for platys? I was thinking of adding a bag of cruched Coral to the back of my filter cartage is that ok? Just Double checking..

[@BigFishLittleFishAquatics]

Hello Megan, So with 40ppm KH, you have c. 2dKH, which is considered low. A bag of Crushed Coral will help you ensure there is plenty of buffer to sustain your pH from crashing. Note - upon adding crushed coral you will notice a slight increase in KH, pH and also GH, but this is normal and all will equalise after about a week, just make sure you follow the instructions on the packet so that you buffer your pH to the level you want for your platys (optimum pH is between 7-8). Thanks for watching the video and Happy fish keeping! On my website I have lots of information for beginner fish keepers, feel free to check it out: www.bigfishlittlefishaquatics.co.uk/

[@andrewrobertsmith7367]

I've had fish for 8 months, I've got 7 platys and 2 mollies all male for now. I've got a 70 Litre tank and the fish are all roughly an inch in length on average. My KH is 4 but drops to 2 if I do nothing so I add a KH buffer which takes it to 6 but I have to add weekly to keep it between 4-6. The GH is between 5-6 in general sometimes reaches 7. (Would like to keep the GH around 8 if possible too) The PH is about 7.8 to 8.0 hence why I don't put more of the buffer in. How can I keep them stable naturally or what is the cheapest solution if I have to use products? The Ammonia has been at 0.2 for all this time (I tried everything to drop the ammonia & very regular water changes and a 4 day fast with the second filter eventually worked) the second filter seems to now keeps it at 0 and the nitrate and nitrites are always stable at the correct values. I do have a 160 litre tank but haven't got around to getting it set up. I've had 4 fish die in this time but never had more than 10 fish in the tank only replacing after two have died. I only realized the KH dropped to 2 when fish died hence why I'm now trying to keep the KH between 4-6. Not sure if this is why they died as it could have also been the 0.2 ammonia that killed them. Any advice is appreciated, thanks.

[@doubledark2]

My tap water has GH 89mg/L, dH 4.98, pH 7.3, TDS 252mg/L, alkalinity 45mg/L - what would you recommend I do to it so I can keep Lake Tanganyika cichlids? cheers

[@BigFishLittleFishAquatics]

Hello! So with Lake Tanganyika Cichlids, these prefer slightly more hard alkaline water to their Malawi cousins, so ideally you are aiming for GH 160 - 320 (9-18dGH), KH is generally best kept at 180-240 (10-14dKH) and your pH between 7.8-9.0 I would recommend two options, my preference with soft neutral water as you have would be seachem products, they have specific buffers for lake Tanganyika cichlids, here is a link to their GH buffer: www.seachem.com/cichlid-lake-salt.php and here is a link to their alkalinity buffer: www.seachem.com/tanganyika-buffer.php You other option would be to add crushed coral to your substrate and filter (in a bag) and let your levels slowly rise... This approach, in my experience is less accurate but if you take your time you will get your aquarium into a good balance.

[@doubledark2]

@@BigFishLittleFishAquatics thanks

[@BigFishLittleFishAquatics]

@@doubledark2 You're welcome

[@martyborst5645]

Hello. I use tap water to fill my tank. It is rather high with regards to the ph…8.2. My KH is between 1-2 according to my API MASTER TEST KIT. Even for the discus I will be receiving that is a bit too low. So here is my dilemma. How can I increase my KH without increasing my PH? Respectfully, Marty B. 1:24

[@BigFishLittleFishAquatics]

Hi Marty, You are in a little bit of a dilemma! Your pH is high, considering a low KH reading, and adding further KH is likely to increase your waters pH higher, putting it probably outside of your Discus's tolerance range. I have a few things I can recommend you try.... 1. With you pH so high my initial thoughts are you might have another buffer present in your tap water, kH is your carbonate hardness, however Phosphates also buffer your pH - first thing I'd recommend is to test your Tap for it's Phosphate levels (API usually sell this as separate tests), these may be keeping you tap pH stable. 2. To understand your 'True' pH from the tap, fill up a bucket, add all usual de-chlorinators, leave for 24 hours with an airstone and test your pH - this will give you a clear reading to work from. 3. Seachem Buffer, along with acid buffer can be used to raise kH and then bring your pH back down - when starting with a set pH this can be tricky to figure out what works best for you, my recommendation is to set up a few test buckets with different ratio's - leave with airstone for 24 hours and see what one leaves you with pH & KH where you want it. 4. Depending on your tank set up, if you are having a fish only tank and plan to understock with a strict water change regime, you may find that your KH is sufficient with weekly large water changes to keep your pH stable. I have kept some soft water fish with 1 dKH without any pH swings successfully with weekly water changes.

[@martyborst5645]

Hello. Thankyou for the information. The topic presented here is timely. Thanks again. Respectfully, Marty

[@BigFishLittleFishAquatics]

@@martyborst5645 You are very welcome - let me know how it goes :)

[@christinamorris2823]

you didn't mention the general ranges of KH or GH that you milght need in your tanks?

[@BigFishLittleFishAquatics]

General ranges I have included in the description of the video, but as said in the video, you are best keeping fish that suit your source water than chasing a specific level... or go down the RO route :)

[@conman20000]

So, I'm wanting to raise my KH and GH with the crushed coral, but that will raise the PH as well, and I don't want to do that. What do you suggest? I have a water softener system for my well water which is why I think I have a low GH.

[@BigFishLittleFishAquatics]

Why do you want to raise your KH too? What's your source water KH in degrees hardness?

[@conman20000]

@@BigFishLittleFishAquatics Well I have a softener so my Kh is 40ppm my GH is 0 and my ph is 8.2.

[@BigFishLittleFishAquatics]

@@conman20000 Does your water softener use sodium? I have heard that many water softeners can be bad for your fish. How is your softener, softening your water?

[@conman20000]

@@BigFishLittleFishAquatics Yes Sodium, it replaces the Magnesium and calcium ioons with sodium ions instead.

[@BigFishLittleFishAquatics]

@@conman20000 I have heard that Sodium in large quantities can be harmful to fish (not experienced it myself so cannot comment further on it) In terms of your KH, you are c. 2-3dKH which would be plenty stable enough, if you do not want to use crushed coral, I would recommend a GH product like Seachem Equlibrium :)

[@tiamariajones6634]

My pH crashed from 6.8 to 6.0 (out of the tap) gh and kh (out of the tap) almost none existant any idea why this has happened

[@BigFishLittleFishAquatics]

Hello Tia, if you are finding that your pH is dropping fast, it sounds like this is due to the lack of KH in your source water. KH is your buffering capacity that prevents acids that are created in aquariums from affecting your pH level, I have a beginners guide video on GH, KH and pH here: kzbin.info/www/bejne/pYnGqaRsrZ6DbsU I would recommend to get a GH & KH test kit and test your tap waters levels, you will ideally want 3dKH (53ppm) or more to maintain a steady buffering capacity. If you also have little to no GH, this is also a reason for concern as those minerals are used by your fish for many health reasons (see beginner video). Depending on your fish and your taps source GH, KH & pH parameters you will have various options to consider, (Crush Coral, Egg Shells or chemicals/powders)

[@scroogehowsshehandle]

Sir I have about 30 baby bettas and I recently purchased a test kit that only comes with 25 test strips I am honestly freaking out as I’ve noticed that I have started dealing with GH And KH issues I’ve tried using sponge filter plants and at the moment I am feeding baby brine shrimp will honestly admit I have not been rinsing the BBS off with tap water will salt from baby brine shrimp cause KH and GH to be low? For fresh water fish like betta

[@BigFishLittleFishAquatics]

Congrats on the betta spawn :) The salt will not lower your GH, but raise it slowly over time. Ideally rinsing the food is best in the long run.

[@scroogehowsshehandle]

@@BigFishLittleFishAquatics hey thank you. except I keep getting a really low reading of KH and GH and as of last night I probably lost 10 betta fry not sure on how to get a stable GH or KH seems like I keep changing water after few days it’s like wth am I doing wrong

[@BigFishLittleFishAquatics]

It is difficult to pin point the cause of this, if you can give me the following info I might be able to give you some pointers: Current tank parameters (GH, KH, Ammonia, Nitrite, Nitrate), Tank Size (Gallons/Litres), Water Change Frequency & volume, Source Water parameters (GH, KH, Ammonia, Nitrite, Nitrate), aquarium temperature, feeding regime & number of fry.

[@narwhalocean791]

can i use aragonite to raise KH?

[@BigFishLittleFishAquatics]

Aragonite, typically used as sand for saltwater aquariums is only really recommendable for freshwater aquariums that desire a very hard water, normally for African Cichlids. Personally if you are going down the natural buffering route, crushed coral is the way to go.

[@bryangonzalez7385]

How do I raise my gh without raising my tds? Gh is 1, but as I'm raising it to 4 my tds goes all the way up to 350.

[@BigFishLittleFishAquatics]

Hello, TDS is a measure of your Total Dissolved Solids, so when you raise GH (which is magnesium & calcium), your TDS will climb. What product are you using as some products (such as seachem equlibrium) have other minerals besides that is required for GH so would add to your TDS volume.

[@bryangonzalez7385]

@@BigFishLittleFishAquatics I'm using equilibrium

[@BigFishLittleFishAquatics]

@@bryangonzalez7385 That would be why your TDS doesn't add up top what you expect your GH to be, equlibrium contains additional minerals that are beneficial for plant growth, it's primarily used with RO water. If you test your GH reading and it should match your desired level.

[@lizcrews5086]

I have a betta fish and snail. My GH is at 0 but everything else checks fine :(

[@BigFishLittleFishAquatics]

You'll want to get some form of minerals in there soon, at the very least calcium for your snails shell :)

[@martyborst5645]

Thanks!

[@BigFishLittleFishAquatics]

Thank you very much for the support!