Backflow (check) valve

[Keith A.]

I'm looking into getting a backflow or check valve for my tank. I've seen several different types, one of which is a spring check valve that I can get at a local hardware store for about $5.00. Basically the the flow of the return pump pushes the water against a disk that is attached to a metal spring. When the power shuts off, then the spring will close the valve preventing the sump from over flowing. The other is a swing check valve which uses a flapper to close the valve (no spring) and is advertised "specifically for aquarium use" for about $24.00 on E-Bay. Would it be OK to use a spring check valve or should I go with the swing check valve? Does anyone have any other options? Any feedback would be greatly appreciated. Happy Holidays...

Keith

[AMDPhenomX4]

Or their are other easier options. Most people just drill a hole in the return just under the water line. I used a saw to cut a slit and it kills the syphon.

The check valves usually stop the water then let some go, stop then go.

[Keith A.]

I already have a hole drilled into each return. The last time our power went out, air never got into the line and we nearly had a bunch of water all over the family room.

[Keith A.]

Wow, I just went from apprentice to regular......

[ryshark]

Do not get a backflow check valve. They will restrict flow from your return pump and eventually they fail. As far as drilling a hole in the return just below the water level.... this is also bound to fail when algae builds up in the hole or a snail is covering the hole etc. What you need to do and is guaranteed to work everytime, is have the nozzle where your return water comes out be high enough to where it will break siphon when the retrun pump is turned off and the water level starts to drop in the tank. IMO thats really the only sure way to go.

[thincat]

If that's not possible, then drill two holes, one on each side so that if one hole gets clogged up by either a snail or moss the other will still break the syphon. Oh, and drill the holes large enough.

[CaptainAhab]

Actually, is your water level was at it's peak (didn't need any topoff) then you already have it adjusted correctly. Your sump almost overflowed.

[Keith A.]

Actually, the holes I have in the returns are just above the water in the tank. Since they are above the waterline, I thought that air would have not problem breaking the syphon if the pump was off. I clean out the holes from any algae or debris maybe about once every month or two. I could certainly do that more often. The returns are 3/4 inch wide and I used a 3/16 drill bit to make the hole in each of the returns (2 returns). Should I try to make a bigger hole? Oh, I also have a SCWD attached to the tubing for the returns. Would that play a part in this?

[ryshark]

Originally Posted by Keith A.

Actually, the holes I have in the returns are just above the water in the tank. Since they are above the waterline, I thought that air would have not problem breaking the syphon if the pump was off. I clean out the holes from any algae or debris maybe about once every month or two. I could certainly do that more often. The returns are 3/4 inch wide and I used a 3/16 drill bit to make the hole in each of the returns (2 returns). Should I try to make a bigger hole? Oh, I also have a SCWD attached to the tubing for the returns. Would that play a part in this?

I don't think the SCWD would make a difference once the return pump is off. But I have never had a scwd

[thincat]

Keith if your holes are just above the water line then that is your Max water level and that's why your tank did not overflow.

[Keith A.]

I know that having the holes above the waterline is a good way to stop back flow. But I had to manually put someting in the hole to allow air in. Otherwise, the sump would have over flowed. Should I drill bigger holes?

[thincat]

If the holes are above water wouldn't it splash water out of it when the pump is running? You would also get alot of air in your system from it sucking air through those holes. I'm confused. How did you get the system primed in the first place to start off?