Check valves on return lines - useful or useless?

[Doubledown]

I am re-plumbing my 120 this weekend and wanted to use a check valve on the return line to keep back siphoning to a minimum during shut down. I currently use a combination ball valve/flapper check valve on my 180s, but it only comes in 1.5" and 2" sizes (my return line will be 1") because I run 2 return lines all the way down the back to keep the area behind the rocks clear.

The 2 returns in the 120 will be at the top and already have siphon break holes drilled into them, I was looking for redundancy. Would the check valve on a 120 be needed? The sump is a CPR CY194 (looks to be around 20 gallon or so) with about a 8 gallon reserve space for back-fill during a shut down.

Should I skip the check valve all together and just put a ball valve on for pump cleaning?

Thanks

 

[pk1]

I think they are worth it if you have a skimmer that operates differently with varying sump water depths-like my ASM. If I had check valves on my tank it would be pretty easy to flip the switch to shut the pumps down and feed the tank. If I do that now the skimmer overflows in seconds (I don't have the valves installed yet).

 

[hansnfrans]

I run a 120 gal with my return nozzle sitting about 1.5" below the water's surface and I don't find it necessary to have a check valve. I have a 40gal sump and I leave enough room for ~5gal of water when it siphons back from the display to the sump. I also don't have a siphon-break on my return nozzle. Everything is fine the way it is.

My return-line is made of vinyl tubing, otherwise I'd put a check valve on it.

In your situation, I'd add a check valve for lil' extra insurance. Who knows....you might accidentally top off a little too much water, and then have a power outage and end up with water on the floor. You never know what kind of crazy things can happen, so I'd rather be safe than sorry in your case. Besides, they only cost ~$15.

 

[CaptRon]

Useless. I wouldn't want to trust one not to get stuck because of calcium and crud when it is needed. I guess you could put some valves above the checkvalves so they can be cleaned periodically. If you do go that route, I'd setup a schedule to test often.

 

[stogie]

I am not speaking from personal experience, but from reading books like Theil and other equipment savvy people they always say they cannot be trusted. they rely on an even surface to close the valve completely. If you have calcium build up or some other organism growing on the valve seat water will leak past.....slowly. JMHO you are better off having a sump capable of handling your tank when the power goes off.

Regards,
Wes

 

[junbug1970]

i use check valve on my return pump for my 58 gal, however i also have the return nozzle slightly under the water level in case check valve doesnt work or fail it will only siphon back little amount of water before the nozzle is above the water surface. Make sure you leave enough room in your sump for the amount of water that will siphon back

good luck

Junus

 

[svb57]

I would not trust the check valves and if you are using anti-siphon holes make sure you keep those clean or you could have a flood.......

A option is to mimic the "new" over flow boxes....hard to explain but the concept is to have an inner and outer "box" where the inner is shorter then the outer and the outer has holes in the bottom. This way the water flows up between the two "boxes" and over the top of the inner one...That way if the power is lost on return pump the water only goes as low as the inner box....

This concept couild be used to create something that would let you pull water from the bottom of the tank but give you the protection of over flowing....

Just some thoughts of mine...

Jim Mc

 

[Doubledown]

Thanks all, I appreciate the info and suggestions.

 

[spider86]

For them to be effective, you have to clean them regularly. They should also be as close to the pump as possible. I have one on my return. I dont clean it, dont rely on it and it no longer works. It did for a couple weeks. I will be removing it.