How do you increase the KH in an aquarium?

[BBfishes]

I my kh is really low. I did water changes and it did not seem to bring it up at all. What product can I use to bring it up to the right level? Is using api PH up sufficient?

 

[Colin_T]

What sort of fish do you keep?

You can raise KH (carbonate hardness) by adding sodium bicarbonate, sodium carbonate, calcium bicarbonate or calcium carbonate.

Adding shells, limestone or dead coral skeleton will help to slowly raise the KH and will neutralise acids in the water causing the pH to go up a bit too. The stuff listed above (sodium bicarb, etc) will also raise the pH.

 

[Essjay]

What do you mean by "the right level". There is no right level for KH. Unlike GH and pH, KH does not affect fish directly; it just buffers pH against changes. When KH is low, pH can drop.
My KH is 3 dH and I prevent a pH drop by doing weekly 50% water changes. This is enough to top up my KH. But I also have low GH so I keep soft water fish. If you keep hard water fish and your GH is high but your KH is low, then yes, you may need to add something to raise KH as hard water fish usually need high pH as well.

 

[StevenF]

To prevent your water from going acidic put a natural sea shell or crushed coral in the tank If your water goes acidic a little bit of the shell will dissolve and neutralize the acid. iONce the PH goes to 7 or above he shells stops disolving and it stops affecting the pH. It works better and is cheeper than any KH booster and one sea shell can last a entire year. Using this my RO water tank maintains a PH close to 7 (for several years). and I have low, about 40ppm , of KH.