3/4" or 1" return - help please

Regulator23 · 03/08/2018, 11:32 AM

thank you. I have 2 reef tanks (125G and 110G) that I am about to consolidate my fish and corals into a new acrylic 180. The 180 is peninsula style (viewed from 3 sides) with a single overflow box on one end. In the overflow box, there are two drain holes that will accommodate 1 1/2" PVC (I'll use 1 for drain and one for emergency) and a single return hole which will accommodate a 3/4" PVC. Here's where I need help.

Do you think it would be advisable to drill the return hole larger to accommodate 1" PVC? Both of my other tanks use 3/4" but I don't have nearly as strong of a pump on them (my new pump will push 4,100GPH at full power).

Not sure if it makes a difference, but I'm also going to run 2 MP40's from the same end of the tank. Flow shouldn't be an issue.

Anyway, that's one question/dilemma.

mcgyvr · 03/08/2018, 11:46 AM

Your return hole size and piping used should be suitable for the pump being used and to not create a restriction..

Typically that would be the same size as the outlet of the pump or greater..

I highly doubt your 4100GPH pump has such a tiny 3/4" outlet..
And NO WAY are you going to get 4100GPH through 3/4" or even 1" really.

oh and FYI.. Typically for a 180G tank having return pump flowrate of up to 1800GPH after head loss.. (typically recommended to have 3 to 10x display tank size) is suitable..
4100GPH is massive overkill unless your sump is in your basement or 10+feet below the display tank

mfinn · 03/08/2018, 03:39 PM

If you are going to use loc-line on the inside of your tank on the return, might as well stay with the 3/4" bulkhead. As far as I know ( or could find) loc-line doesn't come in 1"

Regulator23 · 03/08/2018, 06:13 PM

Got it. I have a smaller pump I think I'll use instead (I was just thinking bigger is better!!). I will have a manifold running off it, but that won't draw much flow at all. Thank you.

kybreos · 03/08/2018, 09:01 PM

MP40 will only make it half way, go with 1.5” Everything and use the big pump. If you want quiet go with DC.

Sent from my iPhone using Tapatalk

jccaclimber · 03/08/2018, 09:31 PM

Other than the ability to fit bulkheads (don't forget the flange size and space to swing a wrench), larger pipes are never worse. If you are using loc-line you can always bring up a large pipe, split, then have multiple loc-line outlets.

laverda · 03/08/2018, 11:58 PM

4100 GPH is a lot of flow and way more then you need. For that much flow you really want 1.5” tubing. I doubt you overflow will be able to handle 4100 gph. It is also very possible your sump will not either. It costs a lot in electricity to pump that much water up 6’ or so with no real benefit. Like uncle said 1800 GPH is plenty.

03/08/2018, 11:32 AM	#1
Regulator23 Registered Member Join Date: Jul 2016 Posts: 9	3/4" or 1" return - help please thank you. I have 2 reef tanks (125G and 110G) that I am about to consolidate my fish and corals into a new acrylic 180. The 180 is peninsula style (viewed from 3 sides) with a single overflow box on one end. In the overflow box, there are two drain holes that will accommodate 1 1/2" PVC (I'll use 1 for drain and one for emergency) and a single return hole which will accommodate a 3/4" PVC. Here's where I need help. Do you think it would be advisable to drill the return hole larger to accommodate 1" PVC? Both of my other tanks use 3/4" but I don't have nearly as strong of a pump on them (my new pump will push 4,100GPH at full power). Not sure if it makes a difference, but I'm also going to run 2 MP40's from the same end of the tank. Flow shouldn't be an issue. Anyway, that's one question/dilemma.

03/08/2018, 11:46 AM	#2
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	Your return hole size and piping used should be suitable for the pump being used and to not create a restriction.. Typically that would be the same size as the outlet of the pump or greater.. I highly doubt your 4100GPH pump has such a tiny 3/4" outlet.. And NO WAY are you going to get 4100GPH through 3/4" or even 1" really. oh and FYI.. Typically for a 180G tank having return pump flowrate of up to 1800GPH after head loss.. (typically recommended to have 3 to 10x display tank size) is suitable.. 4100GPH is massive overkill unless your sump is in your basement or 10+feet below the display tank __________________ Who me?

03/08/2018, 03:39 PM	#3
mfinn Registered Member Join Date: Apr 2002 Location: Olympia. WA. Posts: 8,648	If you are going to use loc-line on the inside of your tank on the return, might as well stay with the 3/4" bulkhead. As far as I know ( or could find) loc-line doesn't come in 1" __________________ 240 gallon soft coral tank 50 gallon lps tank

03/08/2018, 09:01 PM	#5
kybreos Snar snar Join Date: Oct 2003 Location: Pinellas, FL Posts: 929	MP40 will only make it half way, go with 1.5” Everything and use the big pump. If you want quiet go with DC. Sent from my iPhone using Tapatalk __________________ Simplify, trust me... Current Tank Info: 180 Gallon Reef, Apex, Simplicity 320 DC Skimmer, 3 Radions Gen2,1 mp40w, Jebao PP-20, 55g sump, Jebao DCP-15000

03/08/2018, 11:58 PM	#7
laverda Registered Member Join Date: May 2003 Location: Anaheim, CA Posts: 6,902	4100 GPH is a lot of flow and way more then you need. For that much flow you really want 1.5” tubing. I doubt you overflow will be able to handle 4100 gph. It is also very possible your sump will not either. It costs a lot in electricity to pump that much water up 6’ or so with no real benefit. Like uncle said 1800 GPH is plenty. __________________ 240G mixed reef, 29G SPS/LPS clam tank, 50G mixed reef Current Tank Info: 300g mixed reef, 50g cube

03/08/2018, 06:13 PM	#4
Regulator23 Registered Member Join Date: Jul 2016 Posts: 9	Got it. I have a smaller pump I think I'll use instead (I was just thinking bigger is better!!). I will have a manifold running off it, but that won't draw much flow at all. Thank you.

03/08/2018, 09:31 PM	#6
jccaclimber Registered Member Join Date: May 2013 Location: San Francisco, CA Posts: 528	Other than the ability to fit bulkheads (don't forget the flange size and space to swing a wrench), larger pipes are never worse. If you are using loc-line you can always bring up a large pipe, split, then have multiple loc-line outlets.