use 2 check valves or not???

[REEFER1981]

putting together my first everything new reef tank last one bought from a friend. My question is on the return pump should i put 2 check valves just to be safe. I was thing pump check valve then a ball valve then another check vavle with an elbow off that then flex tube to the bulkhead

 

[BonsaiNut]

Personally, I would never depend on a check valve. Therefore, you need to make sure your return cannot create a siphon - ever. No siphon - no need for a check valve.

 

[Fryman]

A check valve will eventually fail. Are you willing to do regular maintenance/replacements of the checkvalve?

I'm with Bonsainut on this one, better to design the system so you don't need it.

 

[DaveMorris]

Number 3 against a check valve. A properly designed system will not need a check valve which will fail. They also cut down flow a little, depending on the type of valve.

 

[Justdrew]

Never used one, never will!

 

[bretcummings]

To many horror stories. Gives you a false sense of security.

 

[munson]

newbie here,,,,my system uses ball valves before and after the pump so it can be isolated,i also have siphon breaks,,,no checks...hope this helps

 

[davocean]

Your return lines should always be high enough for an early siphon break, check valves and drilled siphon break holes fail.

 

[rezaktp]

+++no check valves, it's just a matter of time till they fail! A power outage in the middle of the night, a little calcium buildup on the valve seat, a lot of water on the floor!!!!!!!!!

 

[scarface70706]

seams like a lot of you guys are addressing the problems of having check valves and siphon breaks but not giving any alternative methods to help reduce the risks of back siphons.

Davocean is correct though; if you have your returning lines close to the surface of the water it will break the back siphon. i personally use this method along with a check valve and a drilled siphon break. this way i have at least 3 chances of saving my house from a flood.

 

[atreis]

Don't depend on check valves to prevent a flood. "Stuff" builds up inside your pipes, coats the surfaces of the valves, and they won't perfectly seal. Even if they continue to function overall (questionable), if the outage is long enough, you can still have a flood.

What to do? Make sure your sump has enough extra capacity to handle the siphon. Reduce the quantity of water that will siphon by raising your water outlets up some - once they lower the water level in the tank enough to hit air they will stop siphoning. Use siphon break holes to help reduce the siphon (but don't count completely on that either - they can clog with salt creep).

Whatever you do: test it! It's easy enough to do, just cut power and see what happens.