Return Line Check Valve

Is anyone using a return line check valve?

I have been debating adding one to the systems. Have you had problems with them failing?

Any info would be great. Reviews seem limited...maybe for a reason?

 

Through my research most people do not use them as they can be prone to failure. If your return output nozzles are 1-2 inches below the waterline your sump should be able to handle the extra water and will never have an overflow. That was the advise I used with my recent build and 2 inches of water means about an extra 5-6 gallons of water and my sump levels out with no way to overflow.

Design your sump with extra room and you will never need a check valve.

 

Seems like what I got out of my searches too. Thanks for the help and confirmation.

 

I totally agree.
You can also have 'siphon break' holes drilled in the returns if you want them lower in the tank, yet don't want to drain the DT down to that level in a power out/shut down.
It only takes drilling like 2 x 3/16", or even 1 x 1/4" to let enough air in on a power down to break the siphon, therefore you'd never need to rely on a 'check' valve.
One less thing in the chain that can and will fail when least expecting it to- Murphy's Law

 

Thanks for the info!

 

Check valves and drilled holes are a false sense of security and really not needed. As long as your returns are close to the surface you have the best form of backflow prevention known to man, once the power is shut off only a very small, easily calculated amount of water can possible flow back to the sump until your return is exposed to atmosphere and you have an air gap. We all know water cannot possibly jump up hill so the siphon breaks positively. No cleaning, no failing, no irritating water jetting noise from drilled holes at the surface and no extra parts.

A check valve can be defeated by a single grain of sand, small snail, detritus or food. It does not have to be a catastrophic failure, even a trickle will flood given time and accirding to Murphy's Law you wont be home to catch it or will be in bed asleep. Drilled holes require cleaning and even then whats to stop a snail, anemone or fish from parking over the hole or getting sucked up against it when the power goes off? Or some algae or food or ?? You can clean them 10 minutes ago and the power goes out right now and a piece of frozen food gets sucked up against the hole from when you fed after cleaning. Not good and not reliable.

You can't defeat the air gap and it requires zero maintenance. The only thing you need to do is maintain sufficient freeboard or extra space in your sump to contain a gallon or two of extra water in a power outage, I have a 100G display and the returns are 3/4" under the surface so I get a maximum of 3.5 gallons back to my 30G sump which is easily contained since I only run it about 2/3 full where the skimmer works best. Plenty of room to hide 3.5 gallons extra in a power outage.

 

+1 on what AZDesert Rat said.. its not if, but when they will fail.

Now, let me come clean here. on my 180, I used one. Not to prevent a flood but to lessen the amount of air in my lines on power outages. My remote sump had about 20 feet of 2" pipe between the pump and the outlets in the tank. Draining that much water from the pipe would mean alot of air to be expelled by them when the pump came back on. so I had a check valve. it worked flawlessly for me for 4 years. no issues. But, my system could handle the drawdown anyways so it didnt matter.

my new tank is much less complicated. agian, I have plenty of space for drawdown, but this time since the return line is a foot long with 3/4" pvc... it works wonderfully.

 

I had a check valve in my first tank, had a power outage and it failed and I ended up waking up to a few gallons on the floor. On my new tank I put a T in my loc-line with one nozzle close to the surface and the other pointed lower in the tank. We had our first rounds of serious thunderstorms this morning so before work I unplugged my pump to make sure this wouldn't happen again. My check valve on my old system also cut down on my return flow although it wasn't a large pump anyway.