Check Valve for return

[phish1627]

Working on the plumbing for my first reef tank (40 gallon display with sump). Guy at my lfs told me a check valve was a must for my return plumbing. I plan on drilling a small anti-siphon hole just below the water surface. I also have a fairly decent sized sump that should allow for a good amount of water in case some water siphons back before getting to the anti siphon hole. Is a check valve necessary? They aren’t super cheap and I am reading they aren’t incredibly reliable.

 

[tsharpe291]

I don't believe you need one, ive not used one ever in any tank ive had in the last 20 years.
just make sure your sump can handle it which sounds like you are.

 

[JumboShrimp]

Exactly... @tsharpe291 just beat me to it. Frankly, when I was setting up my two 150-gallon tanks, I bought each return pipe a quality ($) check valve. Come to find out, IMO, if you configure things right vis-a-vis your sump capacity, they are an unnecessary expense. (Not to mention every time I kick off the return pump, the check valves clamp shut with a sonic-boom that rattles the house; slight exaggeration, but it can't be helpful to the system. ) Instead, just point your water return flanges high (shallow) in your tank... which is great for aeration by the way... and physically the water can only backflow into your sump from your tank by 'that' amount when the power gets cut. More than that is impossible. (I don't even have a hole drilled in the flange-- the shallowness of the return into the tank will end the back flow at an acceptable point.)

Bottom line: Have a big enough sump, and test the system by cutting off the power enough times that you can have restful sleep at night-- then put the money you saved into a different part of your system.

 

[Gumbies R Us]

@BeanAnimal

 

[exnisstech]

Not at all necessary. If the sump is too small to handle the back flow when the return is off then you need a larger sump. Never depend on a check valve to prevent a flood. They can be helpful to prevent a rush of air when the pump is turned back.

 

[mfinn]

By placing the outlet of your return pump near the surface of the display tanks water line, you can eliminate the need for a check valve. Along with drilling the hole near the surface of the return line.
A large enough sump is also helpful.

 

[BryanM]

Agreed with all the no responses... Must set up sump to be able to handle the water during a power outage, or whenever you need to turn teh return pump off.

 

[Freenow54]

Working on the plumbing for my first reef tank (40 gallon display with sump). Guy at my lfs told me a check valve was a must for my return plumbing. I plan on drilling a small anti-siphon hole just below the water surface. I also have a fairly decent sized sump that should allow for a good amount of water in case some water siphons back before getting to the anti siphon hole. Is a check valve necessary? They aren’t super cheap and I am reading they aren’t incredibly reliable.

I do not have one . I do have the if I get your termanology correct . Piping that returns the water to the display just under the water surface .

 

[areefer01]

Working on the plumbing for my first reef tank (40 gallon display with sump). Guy at my lfs told me a check valve was a must for my return plumbing. I plan on drilling a small anti-siphon hole just below the water surface. I also have a fairly decent sized sump that should allow for a good amount of water in case some water siphons back before getting to the anti siphon hole. Is a check valve necessary? They aren’t super cheap and I am reading they aren’t incredibly reliable.

Check valves are a crutch
They need maintenance
They can fail due to build up of film and detritus

This is a design issue from the overflow to the sump. Design it such that when the power fails the sump can handle, safely with a buffer, the amount of back siphon. Simple as that. Do not rely on a check valve.

In my opinion.

 

[Privateye]

Agreed. A check valve could prevent overflows from back-siphoning, but so can the hole you made (a "siphon-break").

Check valves can be critical in other situations/designs/applications, but they just aren't needed here. Most overflow kits you buy will have a siphon-break hole. Often times it's under the bend in the elbow.

Just make sure the hole doesn't completely clog over time.