External Pump for Return AND Closed Loop?

Der_Iron_Chef · #1 11-11-2007, 05:41 PM

Does anyone do this? If you have a large return pump that would create too much turbulence through the sump, could you "t" it on both the input and output ends, and use it for both a return AND closed loop?

banditpowdercoat · #2 11-11-2007, 06:20 PM

Thats how I am gona run my sump, Drew. Mag 1800, little to much for a 15g sump, so I'll split the drain to the sump to both ends. Regulated flow fro sump, then the rest dumps near the pump to be returned to the tank without going through the sump.

Not sure how its gona work yet, but should be fine as long as I get the baffles in the sump right

mr_alberta · #3 11-11-2007, 06:34 PM

WHat happens when the power goes out? How do you prevent back siphon into your sump? Also, how do you balance it out that exactly the same amount of water is draining back into your sump vs being pumped out of your sump?

untamed · #4 11-11-2007, 06:59 PM

Quote:

Originally Posted by mr_alberta

WHat happens when the power goes out? How do you prevent back siphon into your sump? Also, how do you balance it out that exactly the same amount of water is draining back into your sump vs being pumped out of your sump?

These are the reasons that closed loop systems are closed. If you attach it into your return system, it isn't "closed" anymore. If there is a power failure, the system would back flow down to the level of the "closed" loop tank inputs. (likely overflowing the sump and pretty much draining the display tank).

You could stop the backflow with a check valve, but no one wants to be THAT dependent on a check valve.

I wouldn't recommend this idea....but I've never tried it myself.

banditpowdercoat · #5 11-11-2007, 07:02 PM

Not going to back siphon. Its a overflow like any other. Just splits into 2 lines where it drains into sump. And I have 2 shutoffs, one on each drain into sump. So, the theory is, I'll throttle the "sump" return to what I need, then leave the "pump" line wide open. Might need to throttle them both a bit though, as I have dual 3/4" durso overflows feeding the 1" drain manifold. heres a pic

Ohh, and for the pump feed line to the tank, I have a swing check valve in there, AND the outlets are just below the water surface, around overflow level. Soo, any drinback will be the same as the overflow anyways. Ohh, and the pump is running on a UPS

Der_Iron_Chef · #6 11-12-2007, 01:53 PM

I get what you're both saying! Thanks for the responses. Bandit...does your method result in lots of microbubbles into the display tank? I would think a direct line into the return section (as opposed to through several baffles) would do that.

banditpowdercoat · #7 11-12-2007, 03:44 PM

Drew, I havent completed my sump yet, but, just running it in a 5g bucket with the one drain next to the pump, no microbubbles. I put on a 90 and a T on the drain kinda like a reverse Durso drain. The drain comes into the 90 first, then to the side fitting of the T. One end of the T is above waterline, the other end is below. The water/air comes into the T, and the bubbles go up the one end of the T, and the water down the other. I'll get a pic to show you what I mean