Will this increase my return flow？

dbq5anlxj · Jul 22, 2020

I'm running a cor 20 (rate for 2000G/H)at 100% right now. There is a single 3/4 tube straight out from the pump then split into two 3/4 return back to my display tank. I just wonder if I bump up the size of the tube just for the pump part and leave the two return line as it is, will this increase my flow? Thanks

lazycouch · Jul 22, 2020

dbq5anlxj said:
I'm running a cor 20 (rate for 2000G/H)at 100% right now. There is a single 3/4 tube straight out from the pump then split into two 3/4 return back to my display tank. I just wonder if I bump up the size of the tube just for the pump part and leave the two return line as it is, will this increase my flow? Thanks

don’t think it’d make a significant difference.. i’m sure it would if you bump up the size of all tubing though!

mfinn · Jul 22, 2020

If you ran 1" or 1-1/4" all the way to the tank, you might see a tiny increase, but you will be limited because of the 3/4" bulkheads ( I'm assuming they are ). But IMO not worth the effort.
If you were to re-drill the holes so you could use 1" bulkheads ( I've heard it could be done, but I wouldn't want to) and find 1" loc-line ( it exists), the flow increase should more.

Bret · Jul 22, 2020

dbq5anlxj said:
I'm running a cor 20 (rate for 2000G/H)at 100% right now. There is a single 3/4 tube straight out from the pump then split into two 3/4 return back to my display tank. I just wonder if I bump up the size of the tube just for the pump part and leave the two return line as it is, will this increase my flow? Thanks

Yes, swapping that 3/4 line to the 1.25 line will increase your flow. the 1.25" pipe has almost three times more cross sectional area than the 3/4" does. The single 3/4" off the return is a huge restriction. the split 3/4" aren't too bad (more volume than a single 1"). how much you gain, I don't know, but would be interesting to record and report back.

For reference I have a DCQ 10000 (~2650gph) return with very complicated plumbing and was only getting ~500gph with a single 1" return split into dual 6" long 1/2" Locline sections at the tank. simply changing those two 1/2" sections to 3/4" netted me about 50gph (10% increase).

I would guess you would see slightly better results.

Bret · Jul 22, 2020

You could also run 1.25" all the way to the tank, and reduce to 3/4" at the bulkheads. The flow will still have to overcome the restriction of the 3/4 hole through the bulkhead, but you will have eliminated a significant amount of restriction in your plumbing from pipe sidewall friction alone. If you are aiming for max flow without re-drilling, it's worth a shot.

dbq5anlxj · Jul 22, 2020

Bret said:
You could also run 1.25" all the way to the tank, and reduce to 3/4" at the bulkheads. The flow will still have to overcome the restriction of the 3/4 hole through the bulkhead, but you will have eliminated a significant amount of restriction in your plumbing from pipe sidewall friction alone. If you are aiming for max flow without re-drilling, it's worth a shot.

Thank you all for the reply. I don't really want to redo all the plumbing. It's a brand new tank and my first tank with sump. So the place I ordered it did the plumbing for me. They did a terrible job on the tank and plumbing even the sump basically everything. I'll change out the one pipe out the pump to 1.25 first then report back. I don't really need much more flow for the sump. I just don't want to run the pump at 100% 24/7. Thank you guys again

laverda · Jul 23, 2020

Your plan makes sense and should give a decent flow increase. A lot depends on your pump. No benefit to increaseing everything to 1.25”. Switching to 1” for the rest might give you a little more, but probably not worth it. Eliminating 90 degree fittings would do more if possible.

Tono · Jul 23, 2020

Agree with laverda and Bret. Since you're running at max speed already any decrease in head and friction losses will help you out. Removing any 90 degree fittings and replacing with 45 or smooth, sweeping sections of larger diameter flex pvc should net you more flow. Just to put it into perspective, 1.25" pipe has nearly 3x the cross sectional area of .75" pipe. Maybe a bit controversial, but I would maybe even consider adding a third discharge line if possible, either drill a third hole or place a return pipe over the edge. You can use a split wye fitting to help.

Bret · Jul 23, 2020

laverda said:
Your plan makes sense and should give a decent flow increase. A lot depends on your pump. No benefit to increaseing everything to 1.25”. Switching to 1” for the rest might give you a little more, but probably not worth it. Eliminating 90 degree fittings would do more if possible.

Neptune recommends 1.25" Plumbing for the COR 20 pump.

https://www.neptunesystems.com/downloads/docs/COR_User_Guide_for_APEX.pdf

" It is highly recommended that your return plumbing has 1-1/4” piping and fittings to obtain the most flow from your COR pump. Smaller diameter piping will reduce the overall flow of water. "

laverda · Jul 23, 2020

Bret said:
Neptune recommends 1.25" Plumbing for the COR 20 pump.

https://www.neptunesystems.com/downloads/docs/COR_User_Guide_for_APEX.pdf

" It is highly recommended that your return plumbing has 1-1/4” piping and fittings to obtain the most flow from your COR pump. Smaller diameter piping will reduce the overall flow of water. "

That does not mean there is a benefit to using 1.25” after splitting it into two lines.

Bigtrout · Jul 23, 2020

The 1.25 to the tee will certainly help. Try just that and see if it makes a difference as that should be fairly easily done.

Rough calculations with flow at 1800gph, 4 feet vertical to a tee fitting, 1.25 inch gives you .5 feet of head loss requiring 4.5 feet of total pump head while 3/4 sits at 6.2 feet of head loss rquiring 10.2 feet of total pump head pressure. Thats a a significant difference! Start there and see if you are happy with the increased flow.

dbq5anlxj · Jul 28, 2020

I installed this 1.25 wye fitting to replace the yellow parts. I'd like to say the flow increased 30% or more. very happy with the result

dbq5anlxj · Jul 28, 2020

I also need some suggestion for the intank flow. My tank is 60×30×21 175G Peninsula and will be sps dominant. Currently, I have two return nozzle and two gyre xf350 but I don't know where should I place the gyre. Should I place it vertically on each side of my overflow or on the third glass(it's kind block the view). Thanks