Return Pump Plumbed With One Way Valve

[Bubblebass]

I've had my tank a year now (120G, 40G sump). It was setup by a local guy who sells stuff from his garage. I'd never plumbed a tank with a sump at the time. After doing my own research and seeing how I would have done things differently, it dawned on me that he installed a one way valve on the pump going to the return. I have read this is a big no no which seems obvious to me. I went to clean the valve since it's been a year while I was researching ways to change it out and realized that without it, the sump will definitely overflow if the valve fails.

What's the right way to plumb the return pump so it won't backflow and flood my house?

 

[mpjmeyer]

Is the return nozzle HOB or drilled through the glass? If it's HOB, you can drill a small hole just below the water line which will prevent a back siphon. My return nozzle is drilled through the glass and I use loc-line hose segments. I adjusted my loc-line to where it's towards the top of the water level so when my apex goes into feed mode, the return pump shuts off for 5 minutes and water level only lowers .5" or so in the main tank until it's below my return nozzle, and water in sump rises only a few inches or so, but no where close to overflowing the sump nor coming in contact with the top of my apex probes where the wires enter. No check valves needed here

 

[mpjmeyer]

I screen shot that from a video I had showing the flow from my Gyre. You can see I have the nozzle close to the top of water level

 

[pdt7361]

I use the same setup as mentioned above - my return line comes up through the overflow and then splits into 2 using loc-line. I have 1 of the nozzles positioned higher so that only a couple of gallons of water backflows into the sump when my pump is off. Having one higher to the surface also gives good surface agitation for additional oxygen exchange.

 

[Bubblebass]

The return nozzle is drilled. I can make one of the nozzles higher to stop the siphon. I have a lot of agitation in the open sump for O2 exchange. I use the return lines as a way to flow behind the rocks right now. Is it common to use the valve? I thought it was a big no-no. Maybe I'm wrong......

 

[mpjmeyer]

I was going to use a check valve but after research and advise from others here on R2R, I decided to return it. I've never had one fail, but I've also never used one on a saltwater tank and don't want to lower my return nozzle, install a check valve and rely 100% on that valve to prevent flow back into the sump. People have told me they've never had a problem, others told me they have had them fail. That wasn't enough closure for me to be confident. I've tested the feed modes multiple times and have nothing to worry about

 

[Roy 9121]

It will only siphon your tank down as low as your return is in your tank. I have a check valve on my return.

 

[AZDesertRat]

Check valves have no place in a reef system. They are a false sense of security and can and do fail, usually when you are not home per Murphy's Law.
As long as your return(s) is only slightly below the surface and you have sufficient freeboard or spare volume in your sump to contain the couple of gallons it flows back in a power outage you will never have an issue.
My 100G display has two returns about 3/4" below the surface. It is simple to calculate the gallons in that area. LxHxW in inches divided by 231. So 60"L x 18"W x 0.75"H /231= 3.5 gallons. My sump is a 30G and it normally runs about 2/3 full since this is the optimum depth for the protein skimmer and where I have my baffles set so 10 gallons of spare room at all times which is plenty to hide 3.5 gallons of backsiphonage in. No check valves to fail, no drilled holes to clean, in fact zero maintenance and I can sleep soundly at night with no worries. We all know water cannot jump uphill so once the returns are exposed the siphon breaks and nothing else can flow back.