Random Wibblings

Got home yesterday (Monday) and thought the water in the tank felt a bit acidic so I did a pH test and found it had somehow dropped from 7 to at least 6. Followed that up with a KH test and it came back as 0! Something has managed to drop it from 4-5 dKH to 0 in a fortnight. No wonder the pH was low as all the buffering had gone. Tested GH as well and this hasn’t changed from the initial 8-9 degrees. The CO2 drop checker has remained on green throughout.

Did a 50% water change which restored the pH back to 7 & the KH to 2-3 degrees. I was contemplating doing this anyway as the cycle seemed to be stuck on full nitrite for a fortnight and ammonia was zeroing daily, plus the plants needed a good pruning and the CO2 diffuser needed a clean. I saved some of the pre-change tank water for later testing and found, to my surprise, that the ammonia was at 1.2 when it had been zeroing daily. It also looked as if the nitrite had just begun to dip as well, coming in at 0.8-1.6. Retested the tank after the water change & ammonia had been diluted to 0.3-0.6 and nitrite to 0.3-0.8. I decided not to add any further ammonia to make sure it was still being processed.

Got home from work tonight to find that I’d forgotten to turn the timer back on for the CO2 so it hadn’t been running all day. Oops! Tested the tank later on and pH seems to have risen a bit to 7.2-7.4 (which I assume is due to the CO2 that was still in the tank water working itself out during the day), ammonia was 0 and nitrite also 0. Hopefully things are beginning to motor now. I’ve added 8ml of ammonia tonight so we’ll see what the state of play is tomorrow.