OK, so now I'm buying a new coil unit for my home's AC. Would you like a new furnace as well, sir?

[Grateful11]

They have tablets you can drop into your drain pan to kill algae, they work, I use them in my
pan and my condensate pump. I couldn't find the type I use, a guy that services our
systems at work gave me about two dozen of them.

Here's some info:

http://www.cleanac.com/AlgaeGuard.htm