I put cornmeal on algae in water....not sure if I put too much or not enough. Also, how long do I wait to see improvement...days? weeks? Has anyone else done this..how much did you put and did it work? I'm talking about 2 small areas near the bank- about 20 by 12 feet each..in a much bigger pond. Thanks for any suggestions.

I think the "normal" way to use corn meal in a body of water is to put the corn meal in a sock or something and just drop it in. It might take as much as 3 weeks to see some effect.

I have a small pond (275 gal) that I treated with cornmeal once. I placed about a cup of it in a sock and tied it off. The algae cleared up in a few days.

However, something about this process stressed my fish. They were having a hard time breathing. So, I removed the cornmeal bag and did a partial water change and they were fine.

BTW, stand back when you remove the cornmeal bag, it smells horrid!

Barley mats or barley extract are also used to control algae and are supposed to be harmless to plants and fish. Haven't had to try it because the fish I have in the pond now are keeping the algae under control.