“Pond Went From Green to Brown Overnight” What’s That All About?

Pond was green water yesterday now today its brown what should I do is this a problem.”

Dr. Johnson:

“I’m noticing that one, crucial piece to your post, that the water was green one day and turned brown/amber the next day. That’s a massive die off of Chlorella / green pelagic algae. There are more than two causes for that but here are the top two: You added an algaecide or something to kill the algae. -or- carbonates have been exhausted and the pH has descended below what Chlorella needs to survive. And, fell fast. So the pH declines to like, 5.5 to 6.2 and it knocks the greenwater algae right down. Fish die next. You can see the same sort of discoloration (de-coloration) in Anachris and Cabomba when the pH crashes. I would *highly* recommend checking the pH and correcting that issue with something like Seachem Neutral Regulator (All the pet shops have it) to bring up the pH fast. Then (if that’s what it was) you can noodle around with things to support the pH on the long term like pHpills. (Home made)

Author: Erik J