my new tank is a 55 gallon and will be fowlr
. i have an overflow box going down to a sump and a mag 7 pumping water back up into the aquarium. please help w/ the following issues:
1. my overflow is rated at 500gph, and the mag 7 is probably between 450-480 w/ the 3 1/2 - less than 4ft head height i have. my overflow box is not filling up all the way and is creating air bubbles when the water splashes down. is this a common issue and is it a problem if the overflow box does not fill up all way? i have no restriction on the pump. i have a ball valve on the return line but it is all the way open. please see picture
2. i solved the problem with the back siphoning issue on the return line. the overflow i am using has a u tube. when i shut the power off, the u tube does not lose siphon...right away. but i let it sit overnight to test it and the next morning i checked the u tube and it lost its siphon. i dont know how much time it takes for the u tube to lose its siphon. if the power goes out for a long time (and it happend in NY last summer) and the u tube loses its siphon, the return pump will overflow the tank...then a nice flood in my basement. is the problem in the u tube? if i shut the power off for a few minutes or maybe even an hour, the u tube has no problem starting back up....its only for long periods of no power.
thank you for reading this and tia
for any replies!!!