Help! PH wildly high, no known cause.

Byron

Responding to your last two posts. Adding the new substrate gravel would not in itself cause ammonia to rise, but the removal of the former stones a day before would have removed bacteria on the stones, so in effect there was then insufficient bacteria to handle the ammonia being produced by the pleco; in a larger tank this has less effect because of the larger surface area elsewhere for bacteria, but in a 10g the removal of the substrat is significant, plus you recently replaced the filter media if memory serves me correctly, so more bacteria lost. I thnk this explains your ammonia rise today. And the subsequent nitrite rise is the second phase of the nitrogen cycle catching up.

Ammonia at .25 is not so bad with a pH of 7.4 (compared to the former 8.4). I would leave the tank, no further water change at this point. I would add another capful of Cycle (I think they recomend one capful to 10 gallons?). Can't hurt, Cycle can't be overdosed, and it is a bit of a jumpstart with bacteria. Test the ammonia later in the day, and the nitrite; monitor what its doing. You've now added the two snails which will increase the ammonia a bit, but I still say this is not going to harm the pleco. But I would aim for stability, so no further water changes unless it becomes necessary.

Water conditioners work instantly. I squirt some in when I start to fill the tank (I use a Python hose attached to the faucet and fill directly from the tap) and have never had any problems.

beckywhite1979

OK, Thanks. I'll keep an eye on the levels

Thanks for all the help!