Plumbing help, return @ 3/4 or bigger?

[burrito]

About to finish my plumbing with the return line. My tank is drilled for 3 1" drains and one 3/4" return line.

I am using a Neptune COR 20 pump which is "œnative" for a 1.25" pipe with a supplied union but comes with a .75 compression fitting too.

I have the parts to plumb it 100% 3/4 hard plumbed and also the barb fittings and silicon hose to use if I want to start soft.

I also have 1.25 plumbing and 3/4th reducers too which would only be used for about 6 or 7" before I reduce to the .75 plumbing.

Should I hard plumb all at 3/4,
All 3/4 except a short beginning of soft tubing
Or start at 1.25 hard for 7" and then reduce to .75 hard.

Only reason I'm considering the large 1.25 is I read there is benefit in starting at the native output but not sold on this.

Thoughts? Reasons why one or the other?

 

[mcgyvr]

3/4 will certainly reduce is total possible flowrate due to the added friction losses,etc..
But depending on the size of the tank and your head heights,etc... that might not be a big deal..

 

[Vinny Kreyling]

Since the pump is 1 1/4 that's the proper starting point.

 

[burrito]

Wouldn’t I just be losing the flow rate anyway after a I switch to 3/4 or does any amount of 1.25 plumbing benefit me. Total head pressure is 3’ of so. Using 2 45 elbows and about 2-3’ of total distance into a 90 locline fitting.

 

[burrito]

option 1- all 3/4 hard
option 2- all 3/4 but starts soft
option 3- starts 1.25, reduces after about 7" to 3/4

 

[Vinny Kreyling]

I would still go with #3.
No matter what the placement of the valve will be annoying to say the least.

 

[burrito]

enter 1 more option.

option 4a/b

was planning on a manifold but then though a manifold on a 2nd pump in the future is what I would do. the cor20 should be able to run both but still leaning toward option 3. is 4 viable or not worth the hassle and complication

on version the manifold comes first but also blocks all space to access lighting and the fuse plans, option 2 the manifold needs to be suspended from the 2 aluminum rails some how but is out of the way, return "comes first"

drain plumbing is all complete (in purple)

 

[Vinny Kreyling]

Suspension can be handled by Clic Clamps, will screw right into the wood & hold real tight.
1 thing - they are made for pipe not fittings.
Why 2 pumps?

 

[burrito]

The stand is all aluminum, any concerns about comprising the structural integrity with a small hole?

 

[mcgyvr]

The stand is all aluminum, any concerns about comprising the structural integrity with a small hole?

define small?
Where is this hole?

unlikely but assumptions are being made based on lack of details..

 

[burrito]

small hole to hold the pipe up by the 2 sections circled in red by these pvc holders. not sure the size but i'd say 3-5mm in diameter at most...

 

[Vinny Kreyling]

If the stand is tubular, thickness comes into play because you should really drill & tap the holes. Otherwise you will have to use self tapping sheet metal ones.
Either way I see no worries here.