slowing down return pump

[eleyan]

The return pump I have seems to be too much for the tidepool 2 sump (laguna 3000 rated at 1283GPH, while the recomended flow rate for tidepool sump is 300-600GPH). If I fill up the sump all the way to the top and then start the pump, it pumps all the water out of the sump and starts running dry. The water level in the tank rises by 1", but in a 135G tank that translates to over 5G, the difference between the high mark in the sump and the pump intake is about that much
I wanted to slow down the flow , and I thought of two ways of doing it. Case #1 is inline valve, and case #2 is a tee with the valve on the side. Which one do you guys use? I like #2 because I can use the split output to drive somthing else (UV sterilizer)

[NaCl_H2O]

I like 1+2 :-D Use the Tee, but put a ball valve in both directions, then you have complete control of flow!

Also, not sure if your problem is completely pump/sump fow rates? It could simply be sump "capacity". when you start the sump return, water rising in the tank is perfectly normal, it needs to rise to a point where it seeks a level based on return flow, and overflow+standpipe flow rate, "Then" the water starts to return to the sump, which could now be "Dry" because it is undersized. You can always pour more water into the sump to get the system to reach equilibrium, but this causes a BIG problem! If you loose power, or turn off the pump, your sump will quickly overflow and you will have several gallons of saltwarer on the floor.

Ideally, your sump is large enough to reach this equilibrium, and still have reserve capacity (empty space at the top) to hold the water that will drain when the pump is off, and until the siphon on your return breaks.

Does this make sense?

[Tim Marvin]

Eleyan, I'm more concerned about your pump..... Isn't that a pond pump? Are you sure it is safe to use in saltwater? The inner workings of some pumps can corrode in time and wipe out your entire tank from leaking oils, heavy metals and other things.... Maybe a mag 9 would be a better choice or another pump suitable for saltwater. Again, I could be wrong, but I have not seen a laguna pump reccomended for saltwater use.

[dow]

I like a combination of the two as well. A valve on your return line allows you to throttle the pump output back to a flow that will work, and a tee with a valve allows you to direct a portion of your water to a fuge or skimmer or wherever you need it.

[eleyan]

NaCl_H2O, your right, it is a sump capacity issue, but the water level in the tank is dependent on the pump flow rate, so a slower up will give less water displacement and will work with a smaller sump ( I guess at this point I want to keep the sump and would like to find a flow rate that will reach the equelibrium without overflowing the sump in case of power outage)
Tim, I got the pump from robert who was using it on his reef for 2 years with no porblems. It looks magneticly isolated like the other water pumps I use.

[witecap4u]

Did you buy Roberts whole setup.

He was supposed to be holding that pump for me, then turned around and said he sold it with his whole setup.

...cs

[eleyan]

I got the sump, pump, sand, rocks and a couple of smaller items. I didn't know you were interested in it, he never mentioned it. I'll trade you for a little bit weaker pump if you have it.

[Dozer]

I solved the same exact issue with a combination of adding a second overflow, and adding a "T" to my return line, attaching a valve to that "T" and feeding it back into the sump. Works like a charm and there is now no back pressure on my pump, which there would be if I simply restricted the output right after the return pump.