This might be a little long because I've tried so much. I have several tanks & am familiar with cycling. I have an axolotl tank, that was cycled, it was bare bottom, 20L, aquaclear 50, runs about 67* ph was 7.6, nh 0, no2 0 & no3 between 5 & 10. I'd cycled the tank with filter I'd been running just for this in another tank. In comes my axolotl...Groot. Water stays fine, I clean his waste out 2xs a day w/a turkey baster, he's only eating live food. I had some water sprite & anubias, a piece of driftwood, a resin ornament & a suctioned on glass vase. Some where along the line the ammonia spiked. I did a 50% water change, brought it down some. To try to make this a little shorter, I removed Groot thinking it lost the cycle some how & let it run its course. The ammonia would just keep getting higher, no improvement. I put the ammosorb packet in the filter, no change. After a couple weeks with no change I put sand in the tank, more cycled media in the filter & put Groot back in, hoping the sand would help generate more BB. Now I've slowly removed every object that was in the tank in case it was the culprit. I've no removed everything I started with & still have ammonia issues. Any ideas & have you ever heard of the tank itself...the sealant causing issues? I'm at such a loss here. At this point I do water changes every other day or so & keep adding prime to keep Groot safe.