Sorry I've been gone so long, it is summer and I have been out of town. I left my betta babies in the 'watchful' eye of my mother, expecting the worst. But what other choice did I have? And I came home to a dead merlin, and the nastiest looking 30 gallon tank one could IMAGINE! Long story short, I spent upwards of an hour cleaning what looked like a horrible outbreak of some sort of slimy algae all over the glass, filter, caves, plants, anything and everything. NASTY! Sky is going downhil fast, he caught whatever mysterious disease Merlin had; the fading color, scraggly scales, ratty, rotting fins, laying at the bottom as if dead, and then perking up at feed time to swim around like normal fr a while, I am just baffled. If anyone thinks they might know what this is and how to treat it, PLEASE HELP ME! The other fish in that divided tank is already showing sings of the mystery killer, or I'd quarantine him.