Vectra L1 + 3/4" plumbing = too much back pressure?

roostertech · Jun 5, 2017

Recently installed an L1 into my Reefer 525XL. I used the

Schedule 40 adapter -> 1.5" to .75" reducer bushing -> 3/4" barb -> 3/4" silicone tube -> red sea barb

I'm running at 40%-50% and getting jet of water coming out of the input side of the pump (which has the screen kit) as well as a low whine from the motor.

mcola78 · Jun 5, 2017

Following as I was about to plumb mine with 3/4" too.

nbagnardi · Jun 5, 2017

I'm also curious about this. i've been thinking of stepping up to an L1 from an M1

reef_ranch · Jun 6, 2017

I wouldn't do it. I find these pumps don't handle backpressure very well.

d2mini · Jun 6, 2017

Why such a large pump with such small plumbing?
And then a 3/4" barb is reducing even further... probably to 1/2" or so.
Even 1" plumbing on my system creates too much restriction with the L1. I don't have any problems doing so but output is reduced. I could run it at 100% and only get around 700 gph according to my flow meter.
I would either upsize everything to 1" or get a smaller pump.

roostertech · Jun 6, 2017

d2mini said:
Why such a large pump with such small plumbing?
And then a 3/4" barb is reducing even further... probably to 1/2" or so.
Even 1" plumbing on my system creates too much restriction with the L1. I don't have any problems doing so but output is reduced. I could run it at 100% and only get around 700 gph according to my flow meter.
I would either upsize everything to 1" or get a smaller pump.

I went with 3/4" because the that's the Reefer return line size. I'm not as concerned with flow loss but more on the noise and back flow issue.

d2mini · Jun 6, 2017

roostertech said:
I went with 3/4" because the that's the Reefer return line size. I'm not as concerned with flow loss but more on the noise and back flow issue.

That's fine, but the L1 has a 1.5" output. It's really meant for a larger tank with larger plumbing. The only reason I have it on my 120g is because I was running Triton which recommends much higher flow through the sump.
For your tank, I would stick to a pump that has a 3/4 or 1" output.
Or try to relieve the backpressure by Tee'ing off the return line with a manifold to run some other equipment and/or just send some water back to the sump.