Siphon Problem

[APFish]

I have been running a 55 BB for about a year now. Now problem besides the usual tightnening issues. This morning I awoke to an empty tank. Here is my theory and what I have done up to now.

I return from the sump into a spray bar that I have running from a hole near the top of the tank down the back wall. To break the siphon, I was told to drill a hole in the 90 at the top of the tank down to the spray bar. It kept shooting water out of the tank so I put a one way valve, a left over from on old HOB skimmer. Seemed to work great in all test runs and up til now. When I awoke, the tank was down to the spray bar, similar to when I did my tests when I first set the sytem up. My theory is that something went wrong, I don't know yet, the GFI tripped, the pump was turned off, and the water siphoned out of the tank.

Now, how to fix it? Should I fill the siphon hole and drill one on maybe the side or bottom of the 90 so that it will spray back into the tank better. What about pressure drop in the line from the water coming out of the hole. The pump is rated at 1200 ish at 4'. I have two seios and so my flow is right were I want it.

Any help would be great. I did a search but ended up empty handed. Maybe a push in the right direction would be great.

Rob

[Little Luey]

the hole to break the siphon should be just below the water line, so that it will let water out but it will not squirt out of the tank. This way if you loose power the water will only drain down to that hole and the water will only go down to where the hole is. Spray bars also cut down on flow quite a bit, how about using a "T", put the spray bar either down or parallel to the water surface and another outlet also.

[Fly Guy]

I bring my returns over the top and down on the front corners so the canopy covers the outlets and there is no piping visible in the tank...back siphon is a non issue

[Wiskey]

Little luey is correct, you need to drill a hole right below the water line. Make this hole big too, that way salt creep does not plug it up. With the one way valve and the hole you have double protection.

Sorry to hear about your empty tank

Whiskey

[APFish]

Thanks for responding guys. My theory about the spray bar was to wash everything from the back forward and then up the front glass and then into the "skimmers" down pipe 90's. Anyway, what is your idea? It really isn't sinking in? I guess your idea is to completly get rid of the spray bar and then just come out with a T and then two outlets up high. Should I point them down, will there be enough turbulance to keep everything moving?

Rob

[Fly Guy]

To be honest, my idea assumes that your spraybars are run by a cls, and that the return is just like a couple of other powerheads in the front of the tank that you cant see.......

If you are doing it for spraybars from your sump return, you need to put two holes in each pipe coming down just below the water line. These two holes are what prevents the tank from back siphoning. No valve is needed and i like to do two small holes in each pipe......

i just went and took a pic for you of a old system in my garage.......this is for a vertical spraybar, so you are just paying attention to the two little holes directly under the 90......the holes are UNDER the water line so they dont spray everywhere.........you should have enough room in yoru sump to deal with it backsiphoning until it reaches the holes