[kgh9555]

Hi All;

First, I want wish you all happy holidays.

Now I seem to have a problem with the water flow in my new 150 gallon tank. I have 72" long tanks, 150 gallons with 2 over flows in each corner. I placed anti back flow valves on the discharge lines and 2 ball valves on the intake lines. After I installed the anti back flow valves, the water started to pulsate on one side only (the side furthest from the pump. I shut the ball value off a little bit and that seems to have solved the issue. But I am concerned about NOT moving enough water. I was at my local fish store and asked them and they have no idea. I looked at there set up and the water appears to much higher in the over flow section where the pipes are than mine. The intake line is totally under water in the store and mine is not. My sump can not hold any more water without over flowing over the dam. Any ideas? Am I too concerned about this?

Looking forward to all the great advice.

Ken

[NATIVEVAMAN]

In just about every double overflow system with one pump the side with the least fittings gets most of the flow.and the side furthest from the pump gets less flow.If one side happens to have the most fittings and be further from the pump at the same time its twice as bad.Any restrictions in the return lines are not needed I would remove them as long as you have anti siphon holes in your return lines.I would also use two return pumps.If the pumps are more closely matched to your return flow the overall flow may increase.Also if one pump quits you will still have flow.

[kgh9555]

Thank you for your response. I believe what you are saying is true. However, the anti siphon valves on the return line are to prevent the sump form over flowing in the event of a power failure, at least that is what I was told. There are holes on the intake piping in the tank for the intake lines so now I am confused <smile> regarding that. Maybe I will remove the backflow values and see what happens when I turn the pump off.

Regarding the dual pumps, I like that Idea. Should I get 2 smaller pumps which equal the size of the one I have for the 150 gallon tank?

[e_baer]

Well, Figures out how much your overflow can drain an hour. Then get a pump to match each overflow. Most likely they will be the same size...in fact, I woiuld suggest it, and then if you have any extra flow from the pump, you can T it off.

[NATIVEVAMAN]

On your return line just before it reenters the tank there is an elbow,in the downward side ot the elbow you need to drill a hole of about 1/8 inch.if the pumps go off for any reason the holes allow air to suck into the pipe and stop the siphon.That will make those back flow valves useless.Then your sump/fuge needs to be large enough to catch all the water in the tank above the notch's in the overflow.So basicly the sump/fuge should be about 1/3 empty to hold that water.