Jebao pump help, not getting expected flow

[nlandgraf]

I am setting up my aquarium again after being down for a few years. With the move I redesigned my plumbing and sump setup, and purchased a new return pump. I have a Jebao DCP 13000 that is rated at a max flow of 3,645 gph. My overflow is setup as a dual herbie; drains are 1" bulkhead and 1" pipe. For a return off of the pump I am using a 1 1/4" return pipe that T's into 2 1" pipes, and each of those T into another 2 3/4" pipes over the back of the tank (4 returns in the tank total).

I was expecting to dial the pump back quite a bit (maybe to 60-65%), but I am running it at dang near full power. My valves on each of my 1" drains are approximately only halfway open; so I am guessing I am probably only moving 600-900 gph.

Is there something that I am missing or not considering that is impacting the amount of water I am moving? I can take pictures when I get home if that helps.

 

[link81]

how much head do you have?
elbows? return pipe size?
i'm certain that the pump "might" be making 3500gph at 0 feet of head. but at about 2.5-3 feet it might be making half that.

 

[dantimdad]

Something is definitely amiss. I am getting about 500gph on my 4000 turned all the way down. I am getting a literal waterfall out of my 12000 on my pond from 11 feet away with 3 feet of height. I would say 3000gph.

I am using 3.4" pipe on my tank with one outlet.

Open up the volute on the pump(impeller housing) and make sure there isn't something knocked loose on the impeller or something in the volute stopping it up.

Also, if you can find one, swap out another known working power supply.

 

[dantimdad]

One other thing: Glue up a test return pipe with one outlet and as few elbows as possible just to see that your return construction isn't the issue. It probably isn't but...

 

[DCR]

600-900 gph is not far off from what I would expect with four 3/4" returns. I would not expect more than 200-300 gph each. Your piping is undersized for that pump.

 

[nlandgraf]

600-900 gph is not far off from what I would expect with four 3/4" returns. I would not expect more than 200-300 gph each. Your piping is undersized for that pump.

I know that the 3/4 return would restrict to an extent, but then I should have to dial the pump back considerably. It is practically at full power, so I didn't think that would be the issue. I am going to unhook and put the return pump in the display tonight and see how strong the flow is. I need to start checking things off the list to limit what the issue may be.

 

[DCR]

That would be a good test. There could be something wrong with the driver that does not cause it to spin at full speed. Measuring the power draw or amperage at the wall against the pump rated would also be useful.