HI....first off, you should determine what is causing your kH to be so low. Reasons for a sliding kH include inadequate water changes, a build up of detritus in the tank and of course, having very low buffering capacity in your tap water.
My first rec is for you to post all your params here and also to test your tap water if that is what you are using and let's see what is in there. If you are starting at a stable pH and it constantly drifts downward, that could be a continued source of stress to your tank inhabitants. If the pH is stable, some fish will adapt and sometimes nothing need be done at all.
If your tap water has a very low dkH and your pH's are making radical drifts, you may need to buffer your tank. Some thoughts include:
1) make sure you are up with your water changes and gravel vacuuming if needed
2) if your water hardness is low (gH), you could consider adding a hardening pillow to the filter...this is slow and takes a long time (crushed coral shell)
3) cheapest and easiest is to add about 1-2 tsp of sodium bicarb to each 50 gallons of tank water with each water change. You dissolve it in aquarium water and slowly add it in while changing the water. Check pH and dkH the next day.
4) the best is if that your water is not so bad, eg, my water is ph7.0-7.2, dkH 2 and gH 2, very soft water, just keep up with weekly water changes and it will come up a bit naturally. I hope this helped. SH
I need it for a 1g, 5g, 10g, and a 29g...
