mamaphish,
Get some tetracycline tablets by Mardel!! I hate to say this, but it resembles a bacterial infection that was rampant some years ago with angels!!
Monitor it closely!!
The tetracycline is going to be expensive as you will need to use one tablet per 10 gallons of water. If anything will help...thius should.
Please understand....it may not be the infection I am thinking of, but the tetracycline will help just the same.
Don't be alarmed as the tetracycline will turn your tank water red. It is advisable to place an extra airstone in the tank for added aeration as well!!
CM