Raising Kh

[cougaran]

Is there any cheap way of raising KH while not killing my PH. My KH test kit came in and I'm running about 0-50 ppm, I need to be up to 100-200 ppm. Right now my PH is perfect at 7.4. I'm running a live-bearer tank. I tried adding in a seperate bag with a little bit of crushed coral in my HOB, but I can't tell you if this had any effect. Any suggestions?

[BASSNMAN]

Common baking soda will raise your KH. If you have live plants you may need to add it weekly. I dump a teaspoon into my filter after water changes to raise my KH from 3 to 8. Start with small amount and test to find the dose you need.

[cougaran]

Thanks, but unfortunately that drives your ph up to 8.2.. I just found an article online that suggests calcium carbonate or shells, corals, limestone, marblechips in the filter. http://www.automatedaquariums.com/tech2o.htm
So I just threw some oyster shells in there, I probably didn't put enough crushed coral in the bag thats still in there. Hopefully these items don't raise PH because it didn't say anything about that.

[SteveM]

AFAIK Carbonate is carbonate - it doesn't matter where it comes from it will have the same effect on pH.

[RoK]

Originally Posted by cougaran

Thanks, but unfortunately that drives your ph up to 8.2.. I just found an article online that suggests calcium carbonate or shells, corals, limestone, marblechips in the filter. http://www.automatedaquariums.com/tech2o.htm
So I just threw some oyster shells in there, I probably didn't put enough crushed coral in the bag thats still in there. Hopefully these items don't raise PH because it didn't say anything about that.

They will increase the pH but livebearers usually prefer higher pH anyway so don't worry about it. Just make sure it doesn't raise it too quickly, they should be fine in pH of 8.2. I'd say just leave the shells.

[mattrox]

Calcium carbonate is not soluable in water to any great extent. It has to react with H+ ions. Since there are hardly any H+ ions at pH 7.4 there won't be much addition to the KH. The effects would be long term.

Na2CO3 or NaHCO3 are soluable. Na2CO3 will raise the pH more for the same KH reading. NaHCO3 is bicarb (baking soda) You add tiny amounts at a time to see how it affects pH. Go slow and measure regularly.

[cougaran]

Ok, thanks, i'll give it a try then with the bicarb, I use to use that to change ph a long time ago in a different tank. I just never dealt with KH before. I'm going to try the shells and the bicarb method and keep testing ph and kh. But i remember my dad saying that when he lived in NY he used to have very hard water and his live-bearers flourished, his other fish had trouble..This hobby has come a long way in 30 years.

[RoK]

So is baking soda the best thing to use to raise KH, without raising the pH a great deal, in your (whoever answers) opinion?

[mattrox]

It will raise pH the more you add the more it rises. It just doesn't raise it as much as Sodium Carbonate (washing soda etc.).

increased KH = pH>7.0