How does carbonate hardness effect fish?

[Hallie]

I bought a different water test kit, this one includes carbonate hardness. After testing the kh reads 240 ppm, possibly higher. The general hardness reads 0, and always has, the majority of the water in my aquarium is well water. Does the kh have an effect on fish? I know it acts as a buffer when attempting to change ph but the ph in my aquarium is just slightly less than neutral.

Nitrites and nitrites both read 0 and ammonia is near 0 too. Not surprising as I have a 55 gallon aquarium with 8 fish total.

[mommy1]

This may help
http://www.americanaquariumproducts....riumkh.html#kh

http://www.cs.duke.edu/~narten/faq/chemistry.html

http://www.oscarfish.com/article-hom...-ph-shock.html

http://mtfb.com/MTFBJUNE/MTFB2%20pag...bsarticle2.htm

Hope this helps

[Hallie]

Thank you, I'd read through a couple of those articles before posting. Everything else seems in good shape so I don't really care about changing the kh if it isn't going to harm my fish in any way. If anything it will just keep my water safe from ph spikes.

I've been attempting to keep a school of neon tetras. They all die always. I have one that is left from the very first school I bought. He must be a year and a half old. Every time I add more tetras they all die. One by one until its back down to the one old tetra. I've tried quarantining and buying them from different stores. I thought maybe the kh levels were harming them but it doesn't look like it. I'm about to give up on them and just stick with platys and phantom tetras. :/

[CrunchyLeaf]

Yours is a story I have heard often with regards to neon tetras. I personally have never had a problem with neons purchased at my local Petsmart. They live long healthy lives.
I have seen many members here though that swear they are very sensitive fish and they often lose a couple of each batch purchased from their fish store. As long as everything else in your tank is good I would chalk it up to weak stock and perhaps try getting some from an alternate source to see if that makes a difference for you.

As to how carbonate hardness translates to fish health, I don't have anything else to add to the posted articles.

[gronlaura]

If your dGH is 0, that may be the problem. You need to have a reading of at least 1 for your dGH - seriouslyfish.com recommends dGH between 1-12. I would thin ka dGH of 4-6 would be correct. Your dKH isn't what matters, that is just the buffering capacity for your pH. It's the dGH that is important for fish health.

[talldutchie]

Carbonate hardness, or carbonate alkalinity is a measure of the alkalinity of water caused by the presence of carbonate (CO32-) and bicarbonate (HCO3-) anions.

and

Degrees of general hardness (dGH) is a unit of water hardness, specifically of general hardness. General hardness is a measure of the concentration of divalent metal ions such as calcium and magnesium (Ca2+, Mg2+) per volume of water. Specifically, 1 dGH is defined as 10 milligrams (mg) of calcium oxide (CaO) per litre of water, which is equivalent to 0.17832 mmol per litre of elemental calcium and/or magnesium ions, since CaO has a molar mass of 56.0778 g/mol.

So something is wrong here. Anything else you can tell me about the water?

[Hallie]

What kind of information are you looking for?

The majority of the water is from our well. I live in south mississippi so our water table is kind of special to our area. It has a lot of ancient plant matter in it.

I have used two different types of substrate, I started with gravel and still had the same water and same issues with the tetras. A couple months ago I decided to switch to sand, and I collected it from our local river system. I choose sand that was clean and dry that had been bleached out by the sun for a while. I have an ultimate goal to use all native species. I can assume the sand has a lot of calcium from mollusks in the river system. But that should raise the dGh, right? I expected the possibilities of the sand causing issues but I had the same water quality with the gravel. I was more concerned with fine sediments not settling, but the area I collected the sand from was larger grains that wash up after the river rises.

[gronlaura]

Are you looking to raise your dGH? If so, for a planted tank you can use Seachem Equilibrium, for an unplanted tank, Seachem Replenish.

[Hallie]

If it isn't going to effect my fish then it can stay where it is. I though maybe it was causing neon tetra issues but I think I'll just give up on them anyways. The one I have left can live alone.