Sump Return Plumbing

BigHildy53 · Jul 11, 2016

My question is about the return line from a sump. Other than a cleaner look, are there other advantages to drilling a bulkhead as opposed to coming over the back of the tank with the piping? Either way I plan on using a check valve to handle any reverse siphoning.

ReeferMaddness843 · Jul 11, 2016

Not that I'm aware of personally. My returns actually are plumbed over the top and then bulkhead through my acrylic euro brace. Sorry for the pic. Nighttime and lights off.
Tank was given to me, so I'm going with what I have. But if it were me, I'd have honestly drilled the back rather than over so could go topless and remain clean looking.

ReeferBob · Jul 12, 2016

You shouldn't use the check valve at all. They gum up and offer little protection. Your sump should be able to take whatever would drain back. Use just under the surface siphon breaks and good sump design instead. Drilled is good but over the back is good too. For returns it is really personal preference. I have 2 tanks, one is over the back and the other is drilled.

dbl · Jul 12, 2016

No advantage one way or the other in my opinion. Mine go over the top and are hidden by a canopy. But I would agree with the above comment not relying on a check valve. Your sump should be designed to take any back flow from the display. The safest in my opinion is to have one of your returns just slightly below the water line. This will provide a break on top of the water line for better air exchange, and also will limit the amount of back flow because you'll get a nearly immediate siphon break.

AZDesertRat · Jul 12, 2016

Check valves have no place in a reef tank, they are a false sense of security, same with drilled holes at the water line.
Design your return so it breaks suction with a slight drop in the display level and your sump with sufficient room to hold that couple of extra gallons and you will have no issues with backflow.

BigHildy53 · Jul 12, 2016

Thank you for the replies and opinions.

tom39 · Jul 12, 2016

I use a check valve in my return but it is not used to reduce drain down of the display but to avoid the blast of bubbles that are introduced into the display when the return line is empty and the return pump starts back up. It has been in use for over 3 years and I have never had an issue.
If it did fail though, I have the return height set to be exposed at almost the same point where the overflow drains the display tank to. Like what others have indicated, a CV is not a fail safe.