Increasing GH and KH

TropicALI

Member
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..
 

Lunas

Member
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.
 
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TropicALI

Member
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?
 

Lunas

Member
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...
 
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TropicALI

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




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


 

Lunas

Member
Leash said:
I acclimate my fish by adding my tank water to their bag slowly over 30-40 minutes
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 5 gallon tank would be good.


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

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




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


 

CindiL

Member
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
 
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TropicALI

Member
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?
 

CindiL

Member
Leash said:
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.

All of the minerals I listed buffer right around 8.2 max.

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?

No because you are replacing carbonates ( even though low) with your replacement water.

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

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 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.
 
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TropicALI

Member
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?
 

CindiL

Member
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 10 gallon or so to the new water.

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

Member
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.


image.jpg
 
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TropicALI

Member
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?
 
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Coradee

Moderator
Member
Threads have been merged to keep all the information in one place, please only create one thread per topic
 

CindiL

Member
Leash said:
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?

Yeah, that would be perfect. A KH of 100 or a little higher will be stable.

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. That's 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.
 
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TropicALI

Member
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


 

CindiL

Member
You can do that. If you GH is currently 179 in the tank that's a great place for it to be. I usually add in 1 cap of replenish per 5 gallon 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.
 
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TropicALI

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


 

CindiL

Member
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.
 
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TropicALI

Member
So what would happen if I put some sea shells in as well as using the seachem products?


 

CindiL

Member
Nothing, that's fine too. Like I said lots of people use both. They use the buffer and replenish with their water they're changing out but the shells are there to hold things in place. In a larger tank alkaline buffer should be enough if you bring KH up to 100ppm. I have seen that people with small tanks 1-5g need the shells in addition to the buffer. Either they're not adding enough buffer or the chemistry of small tanks is just not consistent because of the small volume of water.

"If" your KH got filled up and the PH started to fall then if you had shells they would start dissolving and hold your ph steady.
 
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TropicALI

Member
Oh ok, I thought by adding the alkaline buffer to raise the KH, it would keep the ph stable so it won't drop?




Sorry if the questions I am asking sound dumb, I'm still trying to get my head around it


 

CindiL

Member
Leash said:
Oh ok, I thought by adding the alkaline buffer to raise the KH, it would keep the ph stable so it won't drop?
Ha ha, I think we're going around in circles. So, yeah, the buffer increases KH and helps hold PH steady. If you don't have enough buffer in then it can drop. That is why you want to aI'm for 100ppm or higher. If you are heavily stocked or don't do enough water changes or large enough water changes then the buffer you have added can be used up which then the ph could fall.

If you change out 30-50% a week and re-buffer the water you'll be fine. The shells are optional but is fine to add them.
 
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TropicALI

Member
Oh ok I never knew the buffer could get used up. I thought once it was in the tank it stayed there lol but I guess the fish take in the minerals and deplete the levels? Thanks for your patience! It's 1:16 am here and my brain is not wanting to keep up haha




So let's see if I got this right. If the fish absorb minerals and deplete the KH level, the PH could drop into the acidic levels? If so the acidic water will make the shells dissolve and in turn raise the KH and PH back up?

But if the water's PH stays in the alkaline levels, it won't dissolve the shells?

Please tell me that's correct cos then it makes sense why it's not a bad idea to have shells as a precautionary method


 

CindiL

Member
Yes, that's correct about the alkaline levels and the shells.

The first part is not quite right. Its actually the nitrogen cycle that is acidic. The carbonates absorb the acid holding the ph. When they get used up then there is nothing to absorb the acids and that is why ph will fall.

They do use the minerals that make up GH though, the calcium, magnesium, potassium salts.
 
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TropicALI

Member
Ok so what uses up the carbonates?




I am desperate to understand this so I can go to sleep haha


 

CindiL

Member
Leash said:
Ok so what uses up the carbonates?
Like I said, re-read my post
The nitrogen cycle uses up the carbonates converting ammonia-nitrites-nitrates because the process of the cycle itself is acidic.
 
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TropicALI

Member
Sorry if it feels like you’re trying to explain this to a child. I could just do everything you’ve said but I’m the type of person who likes understand why I’m doing what I’m doing. Please bare with me

So when you said in a previous comment that the carbonates absorb the acid, to me that sounds like when they come in contact with each other the carbonate eats up all the acid and then continues on it’s merry way looking for more acid to chow down on.

Or maybe when the carbonate comes in contact with the acid, do they sort’ve absorb each other?

I think I remember reading something that when the carbonate comes in contact with an acid it will turn that acid into an alkaline.. Maybe that's what happens?
 

CindiL

Member
I think this may explain it all for you

 

Thai Aquarium owner

Member
It is the Kh value of the water that actually buffers the Ph value.
Any value of 3 or less, will affect the kh,s ability to buffer the Ph.
This is why many people in " soft water " areas, will add some Calcium based material to the tank or filter, such as shells, crushed coral or even some Limestone rocks.
 
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TropicALI

Member
So by reading some of that link (thanks btw) the carbonates and acids will cancel each other out right?




Thanks The Aquarium Owner. I already knew that info, just trying to understand what happens when carbonates and acids come in contact with each other


 

CindiL

Member
Leash said:
So by reading some of that link (thanks btw) the carbonates and acids will cancel each other out right?
Yes that's my understanding.
 
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TropicALI

Member
Well thank you so much for all your help




So i'm going to go get some shells from the beach. How much do you think I should keep in my 130L tank as a precaution?

PS: After talking with you today, I thought of what I should write as my signature lol
 

CindiL

Member
I'd say a cup would be fine.

Yeah, what's it going to be? ha ha
 
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TropicALI

Member
Thanks. You can't see it already?
 
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