Increasing kH without chems.

[lkunz]

I've read on other threads that the kH level can be increased by adding crushed coral to your filter. Is this true?

Please expain what crushed coral is. Is is hard saltwater corals broken up? If so, won't this add salt to the tank?

I don't to kill my pet snails so salt is out of the question. Thanks.

-Logan

P.S. I forgot to mention. My tapwater kH is between 35 and 40 ppm. The tanks I have plants in make short work of this.

I haven't had any real problems with pH fluctuation, but I don't want any, either.

 

[RustyRay]

Hard coral skeletons are made up calcium carbonate (CaCO3). Adding crushed coral to a freshwater aquarium only works to increase KH if the pH is below about 7.4 The crushed coral won't disssolve otherwise.

But why are you afraid of using chemicals to increase KH. Crushed coral is a chemical. And the chemicals one can purchase to raise KH contain the same calcium carbonate.

Anyway, the best whay to keep KH high is to keep a low fish load, and to perform water changes. Fiddling with water chemistry is usually completely unnecessary.

 

[JSchmidt]

For the most part, I agree with RustyRay. A KH of 35-40 ppm, though, gives you precious little room for error. It wouldn't take much (e.g., a fish dying & decaying while you're on vacation) for your buffer to be overcome, leading to pH crash.

Crushed coral is handy for gradually bumping up KH. If you're cautious, you can increase KH to a point where you have a bit more of a buffer (e.g., 80 ppm) without affecting pH all that much.

Try adding a tablespoon of crushed coral to a filter bag or nylon stocking. Put that in a filter or anyplace where water will pass by it. The coral will slowly dissolve, increasing KH as a result. You need to test for the first few weeks the crushed coral is in the tank, because you can increase or decrease the amount to cause KH to stabilize where you want it.

This is a fairly simple, slow but dependable way to boost KH to levels that will make your pH a bit more stable.

HTH,
Jim