A couple days ago I shut down my pumps to apply some Joes Juice and was not concentrating on the water level of my sump. Then I heard the sound of water pouring out of somewhere. Low and behold, my sump was overflowing. I never thought that this would happen due to the placement of my returns. WRONG......
WARNING..... if your return are lower in your tank than your overflow, you have the potential for a syphon to develop when your pumps are shut down. As the water level drops in your tank, the syphon will start sucking water out of your returns until air can find its way into the system.
I think I have fixed this from happening again by drilling a small hole in my low return near the normal operating water line. Now when the water level drops, it should suck air rather than water.
... Joe's Juice did kill the Aipstasia.....AWESOME!