Sick Fish - Can't solve the problem

[Aquattro]

Originally Posted by Jaws

I had way more rock in there the first time I treated it and everything did fine.

Well ya, that's the point. You need a certain amount of rock to treat ammonia in that volume, less rock, less filtration. 30 pounds in 300g isn't enough to process waste from all the fish, therefore you get NH3 build up. You have too small a filter.