What really is the GPH of your return pump?

[Aardvark1134]

So this pump is comes with 3/4 , 1 , and 1.25 inch adaptors. No way you should hook it up with 5/8th. If you want close to full flow hook it to 1.25 inch.

 

[92Miata]

Your still going to get more flow starting out larger (max) and then going to inch

This is something people seem to have a lot of trouble with - flow loss is essentially due to friction along the pipe - Ideally you run a big pipe the whole way, but a momentary restriction for a valve/housing/whatever is nowhere near as detrimental as running a smaller pipe.

IE - 10 feet of 1 1/2 into a 1" UV followed by a bunch more 1 1/2 is going to flow much better than just running 1"

 

[Sleepydoc]

completely agree with all the comments regarding pipe diameter. As was mentioned, flow/head loss calculations are essentially complex differential equations but the crux is that resistance increases exponentially with decreasing diameter so moving from 1 ¼” to ⅝” will increase resistance by about 16x. The max flow that pumps are rated for is always with 0 head loss, and most of the pumps we use do not do well against large amounts of head pressure.

 

[Sleepydoc]

This is an AC adjustable pump.

Most people don’t realize that DC pumps are actually AC pumps. The controller creates a variable frequency wave to drive the pump.

I run a Jabeo dct12000, 3100+gph @100%. I use 1inch pipe to get me upstairs, then 2-90s and 1-tee, from there it drops to dual 3/4” pipe , each return has 2-45s, 1-90, snd 1-1” flow meter. Then 3/4” locline inside the tank.

Overall there is roughly 8’ of head pressure.

I run my pump @100%, I get roughly 360gph according to my apex.

Puts things into perspective and how hard it is to “judge” flow.

That’s actually quite a bit of head pressure.

 

[92Miata]

That’s actually quite a bit of head pressure.

Yup.

According to the flow chart for the DCT12000 I was able to find (which is a straight line, so I'm sure its not great) - 360 gph works out to about 14 feet of head - which seems like a totally reasonable ballpark to me for 8 feet of vertical rise and a bunch of undersized plumbing.

 

[SMB]

For my Red Sea 425xl the return hose barb and return pipe have a 3/4 inch ID. The hose barb will take a 1 inch hose but this is a proprietary piece so that is as large as it goes for the last 22 inches into the tank.
I did attach a 1 inch hose to my Hydor 2400 pump (and the hose barb) and repeated the rudimentary flow test and got 1100 gph. I think that will be the best I can do, which is actually just a bit more than the flow rate that I want for the UV sterilizer. So I think I can run the UV unit in line with the return without additional plumbing. I would love to have a manifold but the UV unit can only fit on the back wall of the sump chamber making hard plumbing a real headache
(for me anyway).

 

[See Gee Sea]

I've been wondering this very question ever since I set up my Vectra M2. I wish they gave some guidance as to how many GPH each led on the strip roughly represents.

 

[DCR]

I've been wondering this very question ever since I set up my Vectra M2. I wish they gave some guidance as to how many GPH each led on the strip roughly represents.

The LED bars probably just represent the output frequency or pump speed, which does not directly equate to a flow rate. The flow will also strongly depend on the system backpressure (head) against the pump. You can be a max speed and still get almost no flow if the backpressure is high. They could provide a family of head/flow curves for each pump speed, but I have noticed they are not even providing the full speed head curve anymore on any of the sites. I suspect it was found to inaccurate.

 

[DBR_Reef]

I run a Jabeo dct12000, 3100+gph @100%. I use 1inch pipe to get me upstairs, then 2-90s and 1-tee, from there it drops to dual 3/4” pipe , each return has 2-45s, 1-90, snd 1-1” flow meter. Then 3/4” locline inside the tank.

Overall there is roughly 8’ of head pressure.

I run my pump @100%, I get roughly 360gph according to my apex.

Puts things into perspective and how hard it is to “judge” flow.

My calculator says you should only be getting 307 gph, so I would actually call your result pretty good. Also fairly predictable- of course I did have to guess that you have 9ft of vertical and 10ft of horizontal run. But the OP should be getting around 1900gph from his pump, so either hydor lies, my calculator sucks, or he has a broken pump.