[dschmeh]

Originally Posted by Wasserpest

Easy. Both priming and emptying. It's a secret, but I will share it

Take a vinyl air hose, and shove it up all the way where the bend starts. Then carefully suck out all the air, until <gag> the first splash of water hits your taste buds. Then pinch the hose and pull it out. Bingo!

(the outlet doesn't need to be primed, doh!)

To empty it (so you can replace the dirty acrylic non-lily pipe with a brand new one) you do the same, but blow instead of suck.

Why suck the air out just drill a hole in the top bend and put in a checkvalve hook a airline tube to the airator input on a power head and you will never lose prime . All the overflow boxes on my reeftanks come with this option. (no secret)