I got home from work today and one of my tanks has thick white algea/slime on everything. It's about a half inch thick and waves in the current with 2 inch filaments. Yesterday the tank was fine.
What happened? What is this? I don't see WHITE algea in any of my books. Never seen anything like this grow so fast either. The conditions are wrong anyway.
Last night I did 50% water changes on all the tanks and the others are still fine today (I do 50% water changes 3 times a week). The only thing different about this tank was that when I turned the filter back on, after the water change, the impeller was jammed. I had a new one on hand and put it in, but not without a thorough cleaning of the whole filter unit (it's an Aquaclear). The unit was rather slimey considering I had just cleaned it on the weekend. I doubt the new impeller brought this!
The tank is a 25 Gal sterile tank with 6 young discus and an algea eater. They're all fine but the eater is breathing a little fast.
I don't get it?