Ph, Kh And Rock

[lahainatown]

I have a 33 gallon planted community tank with some Angles and Tetras. I used to use RO water (which I bought in the store) and now changed to tap water after putting in a filter. I plan on setting up a 220 gallon tank this winter, so I want to use my 33 as a test tank to get my water just right. (if that makes any sense) The KH is at 3.36 dH (low) but the pH is at +7.6 (to high) I want to increase the KH to about 5.6 dH and have a neutral pH (7). Is a low KH not associated with a low, unstable pH? My question is, does lace rock or any rock increase pH? Maybe I should go back to using RO water, although on a 220 gal. tank the additives add up

 

[PRW1988]

Calcium rock or base rock tends to raise the PH of a tank. I'd suggest a chemical buffer if you're really looking for a Ph of 7. As for Kh, there are buffers on the market for calcium hardness. Check a LFS that sells marine buffers as they generally sell calcium buffers and maintainers.

 

[TylerFerretLord]

You can do a vinegar 'fizz test'.

Place some vinegar on the rock. If it fizzes it will raise the ph.

 

[celaeno]

vinegar is sometimes too weak an acid, so an alternative stronger acid you can use is api's nitrate test bottle #1, which contains 41% HCl.