Pump too strong??

gkw · 02-11-2006, 08:36 PM

Ok, I put my Mag 9.5 to work and it pump faster for my 2 overflows can put in the sump. I thought my 2 overflows would be enough.

The piping is about 60", two 45* elbow, and three 90* elbow, using 1" PVC.

Here is how I tested. The overflows are at the position of max GPH and the pump are OFF. At the moment, the sump is filled up (not overflow) and the overflows are not active, I then plugged in the pump and the MT is beginning to fill as the water is return to the MT. The overflows are intaking water to the sump, BUT a few seconds after that, the water level in the return chamber is already lower than the pump intake and pumping in a mixture of water and air into the tank. I wait like 10 seconds or so to see if the water in the return chamber will go up, but no....

My return chamber is 12" x 9.5" and the height needs to be less than 10" to be lower than the skimmer chamber. That's about 4 gallons of water with the height at 9".

The only thing I can think of is the overflow. I don't know what they are rated at, but below are some pics of them. Are they too small?

Any ideas?

Thanks!
GKW

RAVEN · 02-11-2006, 09:15 PM

Are your overflow boxes running dry too? If they are they you can try adding a second U tube to the overflow boxes. Other options are adding a ball valve inline in the return line from the pump to the tank. This will allow you to dial in the return flow to the tank to match the maximum capacity of your overflow boxes. This is probably easiest thing to do. Home depot carries ball valves or you can order them on line from most fish supply retailers. You could buy a larger overflow box or a mag 7 pump

gkw · 02-11-2006, 09:30 PM

Actually my overflows are not running dry....the water keeps going to the return chamber, but it's not fast enough for my pump.

I will get a ball valve to direct some of the flow back to the sump, but I really want to use the max power from this pump.

I got this pump for $72 and the Mag 7 is $58.30. That's about $14 cheaper, hmm....but I do want more flow. I might do it if I can't fix this problem without spend anymore money. I am trying to keep my budget low.

Thanks!

kb.bear · 02-12-2006, 05:36 AM

I think raven is right I would add overflow tubes and lower the box in the tank with the combs

kb.bear · 02-12-2006, 05:39 AM

I run a mag 12.5 and a ocean runner 3500 as return pumps on mu 120 gal tank and I have one 2 hose overflow with with 3 overflow tubes. you also need to ditch the air in the overflow tube

szidls · 02-12-2006, 06:46 AM

Do you know the rated capacity of your overflow? It looks physically small for running a mag 9.5. I would also try adding another U-tube in the box. What diameter is your return pipe from the ovf to the sump? And yes adding a ball valve will help to dial in the flow and also is great for shut off during pump maint.
HTH's, Scott

gkw · 02-12-2006, 11:28 AM

everything is 1" PVC or flex tube.

I will try the extra U tube.

Also, someone told me that when to add more water to the return chamber to keep the pump submerge in the water after it's running.

I already took out my sump to make more room for backwash, it will be about 10 - 11 gallons total. I hope that's enough. I will probably try this method first since I already took out the baffles in my sump.

O, and the air in the tube was after I put my old pump back in. That overflow is taking water to the fuge, so it's not very strong. I took the air out and a hour later they went back in.

Thanks everyone!
GKW

RAVEN · 02-12-2006, 03:59 PM

You don't have to use the ball valve to divert water back to the sump. You use it to create more resistance and decrease the flow back to the tank. This way you can dial in the correct flow.

gkw · 02-12-2006, 08:55 PM

If I don't divert the flow back to the sump, I was thinking I can use that for water change. When it's time for WC, I just put a bucket under the pipe and turn the valve. Would that work?

Thanks!