I'm cleaning and giving the tank a total re-do as I type at this moment. I've decided to remove the hide, as it's probably releasing toxic chemicals into the water AND it's troublesome to clean. Eventually I'll add plenty of North American plants and probably a better hide to make the mudpuppy feel more comfortable. Strangely enough, even though the ammonia was really high in the tank, I've noticed that there's a slime covering most of the inner part of the tank, which I've read is beneficial bacteria. The worms that were in the tank were alive too, so I removed them.