Closed Loop through an Overflow.

[sevise]

After a very long battle I've decided to cut my losses and give up on trying to run my sump with 2 Mag18 return pumps. II figured with a 75 gallon sump therw ould of been enough settling time for the ubbles to escape but I was wrong. My plan is to cut it down to a single Mag 18 return and use the second set of overflow/return for a closed loop.

I'm not sure if this will work so thats why I'm posting it. I'll use the 1" bulkhead on my Oceanic Overflow as the feed, and the 3/4" for the return. To prevent air from entering I would just remove the standpipe. My question is whether or not enough water would enter the overflow to feed the pump.

[swissfish]

Did you try to direct the bubbles to the surface by using baffles and the counter current method?
75G should be plenty.

[captivereefs]

Just run the standpipe up and over the overflow wall with some 90 elbows and use an intake strainer.That way the closed loop intake is always under water. I have seen this done before on some local tanks and it works great!

[sevise]

I have tried almost everything to fight the microbubbles. I originally had a 30gal sump, in order to stop the microbubbles I had to use a single Mag9.5 cut down to about 70%. I used baffles but the flow was just to high. So I moved the sump into the basement. Its a 100Gal stock tub, filled to about 75Gal. I wanted to use a pair of Mag18s for the returns. They worked but there were still some microbubbles. I tried baffles and eleaborate PVC tricks but the smallest of the buuble would remain.

I realized yesterday I was fighting the wrong battle. I didn't need to have 1/2 my flow move through my sump. I figure by cutting the flow through the sump in half the bubbles would have twice the time to settle out. Plus I can probobly get more flow through a closed loop than by using the same bulkheads for the sump drain/return.


Good idea about the up and over trick. My question is if I do that how do I insure the water in that overflow doesn't stagnate? A few small holes in the return pipe near the bottom? I'm still a newbie and learning as I go along.