Backflow prevention

[kaiser]

I finally got my wet/dry filter all together. Now I am wondering as to how to keep the water from siphoning back into the filter in case of an power outage. I went by Home Depot and the Valves they sell seem to take a good deal of pressure to open.

[witecap4u]

Don't rely on those valves, they'll get clogged and fail.

I learned that. First time my power went off, my water lever was about 2-3" below my overflow grates and I though the actual overflow box was leaking....NOPE, jus back siphoning on the return lines. I took the check valve out, and it increased the flow a considerable amt.

My old tank had a check valve that had a ball in it, that seemed to work good, but it took it 10-20 sec to stop the flow and and it was loud, but never leaked....cs