Eshopps 300GPH overflow: lift pump setup?

i use this overflow aswell, i turn off and on my return pump all the time, and the 6 months ive been using it, it has never lost its prime.

 

I just bought this same overflow box and am having flow issues. I prime it with the air hose but once it starts flowing on its own the flow rate is very low. Anybody know what I'm doing wrong?

 

Is it slow to the point where it cannot keep up with you return pump?

 

I just bought the same box and love it. Breaking siphon isn't a concern. Water will only be pulled from the display tank while it is "overflowing" into the "skimmer" box. If the return shuts off, water can't flow into the "skimmer" box. Things in the overflow box equalize on both sides of the u tube and the siphon is maintained. In the future, aside from drilling the tank I will never use a different brand of overflow.

 

It could be that the pump is too much for the box. Any idea what flowrate the pump is rated for? I have a ball valve on the return line and a gate valve on the overflow line. Using the valves, I have been able to tune the system so that it is dead silent. In your case, if the pump is too much, you could either get a different pump rated closer to the overflow, or you can put a valve in the return line and throttle it back a little bit.

 

Overflow is 300gph and pump is max 264gph. What I'm saying when I say low is something like maybe 50 gph tops. I mean it's horrible. No bubbles in siphon tube.

 

Ok figured it out. All is well again. Don't put the sponge in the siphon tube. Got it.

 

Glad you got it figured out. I wondered what to do with those sponges too. Still have them sitting in the box lol.