Question:
I have 4 aquariums... biweekly, 15% water change (including gravel vac each time). Ph has been stable for over 18 months at 7.2 but now all four aquariums have dropped off the bottom of the acid scale. I did a 50% water change and added buffit to bring back to 7.0 (severe gravel vac during water change) and within 24 hours the acid level has again dropped off the bottom of the scale.

Could the undergravel filters have blown? I have read off and on about that possibillity. Something is seriously raising the amonia without a corresponding rise in nitrites. Usually that means rotting stuff... but with the aggressive vacuming I can't figure what might still be rotting...

Answer: Most test kits (yellow regent, nessler) will tell you that you are high even though you are not.

But I am using a Silicylate style kit specifically recommneded by Kordon (the makers of Amquel) to be used when using amquel.

The tank is acting as if there is still something rotting in it. But I have eliminated all the rotting stuff I can find... I have been forced to add chemical filtration now to lower the amonia, which I don't like having to do and it is only a short term solution.

The only thing I can figure is that my well water may have changed composition due to fall and all the rotting leaves and rainfall around here... something is definately raising the amonia and lowering the ph.

I guess I need to have my well water tested again. It's gotten to the point that I don't trust my test kits anymore.