Unknowingly barbaric tankowner!

[teapage]

Ok, we'll try the water changes and get back with the parameters. The more I'm researching, I'm thinking the problem was there from the beginning. The tank was used. It belonged to the guy that owns the LFS. I don't think the tank was cleaned good before he came and set it up for us.

[thominil]

If it was just a bare tank, nothing in it when he brought it over, then that is not the cause. More than likely something either died, or you are overfeeding. Not much else that comes to mind other than those two.