return pump too much for overflow box

[TLKAg87]

I built a sump/refugium and everything seems to be ok. However, the return pump is out performing my CPR overflow box. I can't seem to keep the water level in the third chamber (return pump) steady. It gradually goes down to where it is getting very close to sucking air. I ordered a ball valve to restrict the flow on the return line a little bit. Will this do it, or am I missing something?

 

[tdileo]

What time period does this happen over? It could just be the evaporation.

 

[FartyParty]

I always found it better to restrict the pump flow by closing off the baffles on the pump itself, but if your pump isn’t adjustable, the ball or gate valve on the return line is your only option. I like gate valves because they are easy to adjust in small amounts quickly.

 

[TLKAg87]

What time period does this happen over? It could just be the evaporation.

I thought the same thing. Added about a gallon or so of salt water to the return chamber. That water eventually ended up in the DT, with the level decreasing in the return chamber. Takes about 5 to 10 minutes. What is strange is that it has never run dry, just gets low enough to start slurping.

I only started it on Sunday afternoon. I shut it off this morning until my valve comes in tonite from BRS. I don't want to burn up a brand new pump.

 

[TLKAg87]

I always found it better to restrict the pump flow by closing off the baffles on the pump itself, but if your pump isn’t adjustable, the ball or gate valve on the return line is your only option. I like gate valves because they are easy to adjust in small amounts quickly.

I agree on gate valve, but I could only find a ball valve that had barbed x barbed fittings. Candidly, I was in a hurry and didn't look too hard. Do you think a ball valve is ok?

 

[TLKAg87]

I really think I miscalculated the head pressure. I'm running vinyl tubing about 4' almost straight up to the DT. The only 90s are in the return jet. My thought is that the ball valve will create a little bit more head pressure and match up better with the overflow.

 

[KJAG]

I thought the same thing. Added about a gallon or so of salt water to the return chamber. That water eventually ended up in the DT, with the level decreasing in the return chamber. Takes about 5 to 10 minutes. What is strange is that it has never run dry, just gets low enough to start slurping.

I only started it on Sunday afternoon. I shut it off this morning until my valve comes in tonite from BRS. I don't want to burn up a brand new pump.

It’s not an evaporation issue. You need a gate or a ball on the output of the return.

 

[FartyParty]

If your problem is flow, a gate valve should be fine, since adjusting it past the “overflow box matching point” would do nothing except slow your turnover rate further.

 

[TLKAg87]

Thanks everyone. This website is a life saver for a newbie like me. I live in a small town in Texas. No LFS, and I have yet to find anyone in town that even has a saltwater aquarium.

 

[ca1ore]

I always found it better to restrict the pump flow by closing off the baffles on the pump itself, but if your pump isn’t adjustable, the ball or gate valve on the return line is your only option. I like gate valves because they are easy to adjust in small amounts quickly.

Not entirely sure what you mean; but, you should never restrict a pump on the input/suction side, only on the output.

 

[FartyParty]

Not entirely sure what you mean; but, you should never restrict a pump on the input/suction side, only on the output.

I have a sicce 4 return pump and it has an adjustable baffle that you can turn to restrict flow. I have always had a personal preference to adjust those baffles which restrict flow via the manufacturers design vs. having a wide open pump and later restrict the head pressure. All that head pressure will redirect into other fittings and I don’t want the extra head pressure on all the manifold outputs between the pump and the gate valve.

 

[KJAG]

I have a sicce 4 return pump and it has an adjustable baffle that you can turn to restrict flow. I have always had a personal preference to adjust those baffles which restrict flow via the manufacturers design vs. having a wide open pump and later restrict the head pressure. All that head pressure will redirect into other fittings and I don’t want the extra head pressure on all the manifold outputs between the pump and the gate valve.

I’m not familiar with that Pump, but as mentioned, generally you never restrict the input. Restricting the output actually prolongs the pumps life for most, if not all brands out there.