I set it for about 1/2" above the point where the main chamber meets the tapered neck. I do this regardless of how much algae there is, but if you want really wet foam, perhaps experiment with 1" above this point.
I mean to raise the riser tube until the water level in the main reaction chamber is about 1/2" above the point where the tapered neck is glued to the 6" body. A slightly wetter foam will help remove more algae.
ah ok i get ya now, thanks for clarifying that. Problem is i really cant see where the water level is because there are too many bubbles in the chamber. How much should the tube move? It feels like it can only move up or down like 2 inches. is it stuck or is that all its supposed to move?
