pH problems

[bunderson]

Hi,

I have a 20G planted tank that has been up and running for 1.5 years now. I use SeaChem alkaline buffer and DIY CO2 to regulate pH, and I have had no real problems since the tank stablized after setting up. Now I cannot keep the pH up...I raise it to 7, and a day later it's down to 6 or below (bright yellow on the test, and I've used two different bottles of pH test reagent). Nothing else has changed....although I stopped using the CO2 until I get the problem worked out. Could something be chelating the buffer out? I'm afraid the continued addition of the seachem alkaline buffer could raise the other salts too high for my fish. I also supplement with seachem Equilibrium to keep the gH up in our soft San Francisco water. Any help would be greatly appreciated.

Thanks!

 

[PumaWard]

First, I wouldn't do anything purposfully to raise or lower pH, especially through chemical means as they are very, very rairly stable. Next, you need to find out what your kH which is your buffering capacity. The buffering capacity determines how stable or unstable your pH is. I think that 4 degrees kH is a stable, and anything above is stable while below, you may run into problems. Could you also tell us what the pH out of your tap is after you have let it sit out in a bowl or cup overnight?

If your kH is low, you can add a small amount of baking soda, but be careful with it as it can also cause pH to go up.