Flow meters.. are you shocked how little flow you are getting???

Mortie31 · Feb 26, 2017

I got my first controller last week and 2 flow meters for my return pump lines, now I was expecting to see some reduced flow, I guessed about 50%, due to several bends, and under rock work return piping on one line and an ocean motion on the other return line... I have 2 8000L Jecod return pumps... guess what flow I'm getting at full power?????
1975L/hr on the under rock line and 1618L/hr on the ocean motion line, it was 1459L but I removed the direction beak and it rose 150L... that's less than 25%!!!! I have a head of 48" so not huge... it just goes to show how much the pipework and fittings reduce the flow, who would of thought the directional beak would of had such an impact... I know the Jecod pumps are not the most powerful, I might try to get my hands on a more gutsy 8000L/hr pump and see what the difference is...

Brew12 · Feb 26, 2017

Mortie31 said:
I got my first controller last week and 2 flow meters for my return pump lines, now I was expecting to see some reduced flow, I guessed about 50%, due to several bends, and under rock work return piping on one line and an ocean motion on the other return line... I have 2 8000L Jecod return pumps... guess what flow I'm getting at full power?????
1975L/hr on the under rock line and 1618L/hr on the ocean motion line, it was 1459L but I removed the direction beak and it rose 150L... that's less than 25%!!!! I have a head of 48" so not huge... it just goes to show how much the pipework and fittings reduce the flow, who would of thought the directional beak would of had such an impact... I know the Jecod pumps are not the most powerful, I might try to get my hands on a more gutsy 8000L/hr pump and see what the difference is...

I believe the Jecod pumps have a maximum head of 14ft. You will get much better results if you find one rated for the same flow with a max head of 20+ft.

Mortie31 · Feb 26, 2017

Brew12 said:
I believe the Jecod pumps have a maximum head of 14ft. You will get much better results if you find one rated for the same flow with a max head of 20+ft.

My head is only 4ft, they should be able to handle that little.... I'm not questioning the pump really just how much loss we get due to pipe fittings and bends, it will be interesting to see if this is consistent with the higher rated "pressure" pumps rather than circulating pumps..

Brew12 · Feb 26, 2017

Mortie31 said:
My head is only 4ft, they should be able to handle that little.... I'm not questioning the pump really just how much loss we get due to pipe fittings and bends, it will be interesting to see if this is consistent with the higher rated "pressure" pumps rather than circulating pumps..

There is no difference to the pump if between fittings and pump head height. When you crunch the numbers of losses due to fittings it gives you a number in height. For instance, a 90 degree fitting may be the exact same flow restriction as adding 4" of height. The max pump head is where the pump goes to zero flow in its curve. So, a pump rated to 2o+ ft will give much better flow through your system than this one rated to 14ft

NanoDJS · Feb 26, 2017

Brew12 said:
There is no difference to the pump if between fittings and pump head height. When you crunch the numbers of losses due to fittings it gives you a number in height. For instance, a 90 degree fitting may be the exact same flow restriction as adding 4" of height. The max pump head is where the pump goes to zero flow in its curve. So, a pump rated to 2o+ ft will give much better flow through your system than this one rated to 14ft

so true this is the magic part missed by people , a 90 is like 6' of lineal restriction nobody does the pump loss correctly , example i must use a mag 18 on my system to get about 800 at my nozzle in the display lolz so i am loosing around 1000 gph due to restriction and 90's only with a head of 7' basement to 1st floor

TylerS · Feb 26, 2017

How big is your pump outlet diameter, and how big is your plumbing diameter? Do you have any areas with smaller diameters than your piping? Loc-line for example?

Mortie31 · Feb 26, 2017

Brew12 said:
There is no difference to the pump if between fittings and pump head height. When you crunch the numbers of losses due to fittings it gives you a number in height. For instance, a 90 degree fitting may be the exact same flow restriction as adding 4" of height. The max pump head is where the pump goes to zero flow in its curve. So, a pump rated to 2o+ ft will give much better flow through your system than this one rated to 14ft

I appreciate this, and as I said did expect 50% loss, but I wasnt expecting 80% lol, it's not a problem the tanks been running for 4 years like this, and I still have 5x flow through my sump.. I just thought I had more flow, I think now that apex and GHL have flow meters a lot more will see just how much is lost. The duckbill nozzle amazed me most 150 L lost, I dread to think how much locline as someone posted will reduce flow..

Fritzhamer · Feb 26, 2017

I've always read that one 90 degree elbow is the same as one foot in head pressure. I used to use PVC for returns and plumbed it to look nice. Now I use clear tubing for my return lines and I have had to dial all my pumps way back.

NanoDJS · Feb 26, 2017

yes its roughly about 1' per 3/4" or 1" 90 and around 6 -9 ft of straight tube equivalent depending on the pattern short or long turn

TylerS · Feb 26, 2017

Those rules of thumb completely dependent on flow rate and in many cases aren't true for the flow rates in this hobby. As an example, in the newest BRS video 2 of the pumps have almost no head loss while 2 pumps have head loss. The only difference is the flow velocity in the pipe.

Focus your efforts on eliminating pipe diameter reductions or increasing pipe diameter for the largest improvements.

Fritzhamer · Feb 26, 2017

The two pumps with (little) head loss were what they should have been for a few feet and two 90s or four 45s. The pumps with significant head loss were pumps that require a much larger diameter pipe but were forced into a small pipe due to the limits of their rig. They had to significantly reduce the pump output fittings to fit the rig. He stated a few times that he thought there would be significant added head pressure due to using too small a pipe.

In my case I had five 90s and five feet of straight pipe. I had to keep my pump on the higher settings. When I switched the return plumbing to vinyl tube and two 90s I had to set my return pump to the lowest setting.

TylerS · Feb 26, 2017

Fritzhamer said:
The two pumps with (little) head loss were what they should have been for a few feet and two 90s or four 45s. The pumps with significant head loss were pumps that require a much larger diameter pipe but were forced into a small pipe due to the limits of their rig. They had to significantly reduce the pump output fittings to fit the rig. He stated a few times that he thought there would be significant added head pressure due to using too small a pipe.

In my case I had five 90s and five feet of straight pipe. I had to keep my pump on the higher settings. When I switched the return plumbing to vinyl tube and two 90s I had to set my return pump to the lowest setting.

Not sure where you're going with this. The head loss from a 90 is related to the velocity in the pipe with the equation K*v^2/(2*g), and everything but v is a constant. So clearly the head loss from a 90 degree bend is equal to 1' at only 1 velocity. So in the BRS video which used 1" pipe in all cases the first two pumps had such a low velocity that there was almost no head loss from the turns (2' head loss would have had a significant affect on a 10' pump) and the higher flow pumps had head loss from the pipe and turns.

So when you're designing your return line you can do the best you can to reduce the number of bends, but the best bang for your effort will be simply using a larger return line which would give a lower velocity (which is proven in the video).