Backflow Prevention Input Needed

untamed · #1 11-22-2007, 07:07 PM

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.

Joe Reefer · #2 11-22-2007, 09:34 PM

What kind of compartments are you planning to have in your sump?

It can be done but I think things are simpler having a dedicated CL pump and a dedicated return pump. I know that having one pump is your goal but in the end your going to have a lot less headaches.

Untamed: I couldn't wrap my head around that idea either.

bassman · #3 11-22-2007, 09:41 PM

Quote:

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.

Joe Reefer · #4 11-22-2007, 10:35 PM

Ok an 8ft sump is going to work well. I was thinking around 4 or 5 footer. You should be able to double or maybe even triple that number with the size of sump your thinking. Is there any reason why you couldnt make it wider too?

bassman · #5 11-23-2007, 12:12 AM

Quote:

Originally Posted by Joe Reefer

Ok an 8ft sump is going to work well. I was thinking around 4 or 5 footer. You should be able to double or maybe even triple that number with the size of sump your thinking. Is there any reason why you couldnt make it wider too?

That's what I was thinking. No, the space I am building it in is only 17" wide. No biggy, it should be plenty.