Backflow Prevention Input Needed

[bassman]

Originally Posted by untamed

You said that you were going to use a powerful pump...so I'm envisioning that you are flowing thousands of gph through the sump- through the OM 8way - through the overflows - back to the sump.

Generally, you don't want to turn the sump volume that fast. If there are any bubbles in the sump (from the returns or skimmer), they could get sucked up in the high flow and get shot into the display tank.

Someone else on the board here was talking about an idea whereby they were going to use 1 single pump to drive the return and a CL (sort of closed). The design was such that the pump would pull from the sump AND from the display tank at the same time. In theory, this seems like it would reduce the flow through the sump...but I couldn't get my head around the backflow potential of that kind of setup.

Gotcha, I see what you mean now.

I am going to throttle down the pump for a flow of somewhere around 800-1200 gph, nothing too intense.

The sump plans change by the minute. LOL I may build it even bigger now, deeper. Probably 36" deep x 8' long x 17 wide. I will build a good sized bubble trap. The rest of the sump will be open. I have a 30 gal fuge that will drain into the sump as well. The bubble trap will be on the opposite side of the sump from the return pump, over 7' away.