Increasing GH and KH

Ok so I had a fish die a couple of days after buying it, I rang my LFS to see if they could replace it and their policy is to test my tank water before they can replace. They tested it and the ph 7.1, nitrates around 10 and the GH was low. She didn’t give me the exact amount but said it was very low which is why my fish died. I have guppies, swordtails, mollies and neon tetras. I’m sure my tetras were happy with the water being soft but the rest of my fish not so much. She also told me that’s why I’ve seen my fish having a skitz rolling and flipping about the gravel every now and then. So I brought some Aqua One tropical conditioning salts and an API GH & KH test kit. Done a little research on what the GH and KH mean and I understand the basics of it.

The salts say to add one scoop (which equals 2 grams) for every 10 litres. My tank is 130 litres, so I’d have to add 13 scoops but was told not to do it all at once because it will shock my fish. She said to add 6 scoops when I got home which I did, and then add the other seven scoops in two or three days.

I put my test kit to use and tested my tap water. The KH was 35.8 ppm and GH 53.7 ppm. Then thought I’d test my tank water (which was about 5 hours after I added the salts) to see how much the level had changed but I still got the same results as the tap water, even after having added 6 scoops of the salts. My first thought was maybe the instructions of 1 scoop per 10 litres was for a safe and gradual climb of GH, and my second thought was maybe they’re not very good salts..
So I added 1 scoop into one litre and tested that. The results I got for GH was 179 ppm (much better) but the KH was still the same as the tap water being 35.8. I thought adding the salts would increase the KH as well as the GH? I have read that having a low KH can also cause fluctuations to the PH but I’ve always had a stable PH of around 7 for tap water and tank water so I’m a little confused. Could someone please help explain why my KH hasn’t changed?? And why my PH isn’t affected by a low KH?

I have since mixed up another 14 scoops and added it to the tank. 20 in total. I’ll test the results after posting this and comment them below. I’m hoping it should have increased the levels a bit but not dramatically so as to cause my fish stress.

My last question is about what level of KH and GH I should have. I’ve done a little research and found my KH should be 100-150 and GH for livebearers at about 200 or more. If you agree or disagree with this please let me know as that’s what I’m aiming for, unless told otherwise. Sorry for the long post! Hopefully the more information I can give will help to get the best answers

GH is now 71.6 ppm so has gone up a little bit KH is still 35.8 ppm..

 

Kh and gh will raise the pH of the water in all likelihood that fish did not die from your tank water though. Gh and kh are simply not something that is a make or break your fish need this much or will die situation...

Your adding salts... Not an expert but you should be very careful tetras and others are sensitive to salts...

Kh easiest way to raise is baking soda do it 1/4 teaspoon at a time.

 

I will be setting up a separate tank for my tetras. I have had a couple of fish die in the past a few days after buying them. My LFS keep their tanks GH around 268 ppm so the fish going from that to my 53.7 is a pretty big difference that i thought would cause extra stress and sickness, leading to death. I want to do everything i can to minimise the chance of it happening again

Maybe @CindiL can help?

 

Not on its own but you should read up on acclimation and in particular drip acclimation.

The tetras are sensitive to salt but tolerate a little.

Guppies are very adaptable species and should not have issues with either water I don't have experience with mollies or swordtails but I know mollies and guppies can crossbreed and unless you want muppies only males should be in tank together.

That rubbing on the gravel is called flashing and is a sign of skin irritation. I would look close at the skin of the fish for signs of ich it should look like salt on the skin of the fish...

 

I acclimate my fish by adding my tank water to their bag slowly over 30-40 minutes


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I've also heard that they can cross breed but will generally stick to their own species. Many people keep guppies and Mollies together and don't have problems so like them I'm taking my chances back to the topic though the questions I need help with are about the gh, kh and ph


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You may wish to increase the time you acclimate doing it slowly is advised. Also even trusted LFS should have a quarantine time. I would keep a bare bottom for this either a critter keeper or 5g tank would be good.


Well crushed coral either as a substrate or in a bag in your filter will help with kh and gh

 

They don't have ich, it's common for Mollie's to flash when they are needing more minerals like salt in their water


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I done a quick Google search and found this to explain further what i was meaning.

 

"Shimmying is a symptom rather than a single disease, and an indication that a fish no longer has proper control of its nerves and muscles. It occurs when fish are under severe stress, most often because of environmental problems.
The classic scenario is when mollies are kept in soft or acidic water conditions. Though tolerant fish in many ways, they do not do well in soft or acidic water, and it is very common to see mollies kept that way start to shimmy. To varying degrees, almost all the other livebearers sold to hobbyists are sensitive to soft or acidic water conditions, and consequently the shimmies may be seen among any of them kept in the wrong water conditions."

I know all the benefits of adding aquarium salt and IMO it's better than not having any at all, especially when it's what the fish are used to. I just need some advice on the questions I asked in the original post


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Hello, GH and KH can be tied together. For instance if you were to add coral, aragonite, limestone etc both would rise. This is because the shells as they dissolve would put out both calcium and magnesium chlorides (salts) and also calcium and magnesium carbonates. It sounds like the product they sold you is just the salts and no carbonates which explains why your GH has risen and your KH has not.

I don't know why they sold you that product as it wouldn't be my first choice. I would actually just buy some coral, plain sea shells, a holey rock decoration (limestone) or aragonite pieces or sand. This will slowly raise them both. You will probably need to keep using the salts for your GH at water change time. If you get can a hold of Seachem Replenish I'd recommend that. It is a pre-mixed liquid and will allow you to easily get your GH up where you want it.

You're right the livebearers are probably dying from the low GH, they cannot live without high minerals for very long. They are some of the only fish I know besides African Cichlids that require lots of minerals. I keep my GH at about 180 or above and all my fish do fine. You do not need to move your tetras out. Most fish will adjust to higher minerals then vice versa. I have neon and glow light tetras as well as a gourami and a german blue ram and they are all happy in my GH.

As far as why your ph is stable with a KH of 2 or so (35dKh), it comes down to bio-load of the fish you have, size of the tank, how large and how often your water changes are. It does not allow for any mistakes and I think you've been lucky so far

 

Thanks heaps for your explanation in the first paragraph! Can I use regular sea shells from the beach?

If I was to buy a limestone decoration that was fairly big, would it release a lot or would it slowly release the same amount as a small piece would? Hope that makes sense.. Just don’t want my GH & KH to sky rocket quickly or end up being higher than my desired amount because I have too much limestone.

When using my salts at water change time, won’t the KH levels in my tank be diluted by the replaced water as the salts only raise GH?

My LFS sell a fair few seahem products, does the replenish raise GH and KH?

I will be needing to raise the GH and KH to the level of what’s in my tank, of each bucket of tap water before I tip it into the tank won’t i?

 

Yes, I usually buffer and add minerals like replenish to my water I'm about to change out so it matches the tank water fairly closely.

 

No because you are replacing carbonates ( even though low) with your replacement water.
This part still has me a bit confused. Say for instance my KH was at 100 and I done a water change, because my tap water has a low KH wouldn’t that mean the level would now be less than 100 from dilution?

Tell me if I’m wrong but I’m now thinking you might mean that after a water change my KH level may go down but the shells or what not would increase it back to 100 after a few hours or so?

Replenish only increases GH, not KH. You can use the shells (yes you can use sea shells, just boil them for a couple minutes.) If you buy them, make sure there is no coating on them. Your other option is to use Seachem Alkaline buffer to increase your KH at water change time and then have the shells in your tank to help hold things steady.
I live on the coast of Tasmania so finding shells on the beach is very easy, I could even get the sand stuff that’s made up of tiny shells and crushed shells if that would be okay or do they need to be proper shells?

 

Well yeah, if your tank is at 100 dkh from using some type of coral or shell and you replace the water with straight tap and no buffers then it will drop for a couple days until the shells can dissolve some and increase it. Shells are slow and steady.

I personally think with a water change its best to add a buffer to the replacement water like Seachem Alkaline Buffer which allows you to increase your KH immediately. Baking soda or bicarbonate of soda will do the same thing. You add in 1/2 tsp per 10g or so to the new water.

I wasn't sure what sand you meant? aragonite maybe?

 

If i add baking soda to a bucket tap water for a water change until i get the same KH as the tank, that should mean i'd have the same PH in the bucket as the tank also then wouldn't it?



I’ll post a picture from google that’s like the sand I’m talking about. It’s not really sand, more like lots of crushed up shells but is along the beach.

 

Never mind about the above questions to do with baking soda and the crushed shells, i've decided I’m going to get the seachem alkaline buffer and replenish as they give results straight away.

Would a KH level of around 100-150 be good? And around 200 for GH?

And just to clarify, i wouldn’t need to have any coral or shells in my tank when using the seachem would i?

 

No, but its not a bad idea to have both. Thats what most people do. Add the buffer to their water change water and have some shells also "just in case".

Your local sand with the crushed shells looks perfect for that. I would just say maybe boil it for a few minutes first so you're not introducing any new pathogens.

 

Oh ok, I was going to slowly add the replenish and alkaline buffer to my tank to get the levels where I want them because that would work much faster than the shells


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You can do that. If you GH is currently 179 in the tank thats a great place for it to be. I usually add in 1 cap of replenish per 5g water I change out then I usually re-test the tank and add a little more if I need to.

The buffer you'll want to add in 1/2 tsp per 20g, wait an hour or two, test, add in more.

You don't have to add the shells, it does look like a pretty substrate though.

 

Yeah it does. Could I still put some in or just use the seachem products?


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Its up to you. I don't think the shells will be enough for your GH and KH unless you did your entire substrate with it, then it probably would.

You can just use the Seachem products, you don't have to use the shells though.