Pump size?

pastelball · 04/16/2006, 11:05 AM

What size pump do you think would be good for 1 1/2" drain?
I might stick with the Mag drive line as you can find them online for a decent price. The return will only be about 4 to 5 ft. Any other suggestions would be great.

unit91 · 04/16/2006, 09:02 PM

well, 600pgh is the max flowthru for my 1" drain... so you can basically calculate it... 600gph x 1.5 = 900pgh... so if you want to stick with mag...(god knows why?!) I'd guess you need a mag 9... although if I were you, I'd MUCH sooner opt for one of the vastly superior brands: ie, eheim 1262, poseidon PS3 These will run many years longer and a million times more quiet.

sjm817 · 04/16/2006, 09:06 PM

Assuming you are posting about a return pump, size it to 3 - 5X display size after headloss. For example, a 100G tank should have 300 - 500 GPH return flow after headloss.

Jaygar · 04/16/2006, 09:31 PM

Since flow depends on pi x square of the radius, increasing the diameter by 50% would increase the flow by ~2.25

If flow through a 1" drain is 660 gph then flow through a 1.5" drain should be ~2.25 x660=1485 gph

So wouldn't we be looking for a pump that will deliver 1485 gph adjusted for head?

sjm817 · 04/16/2006, 09:42 PM

You size a return pump by display size, not drain pipe size.

and...

To Reef Central

Jaygar · 04/16/2006, 10:00 PM

I have no argument there. My comments were really directed at the math re flow rate vs diam.

unit91 · 04/16/2006, 10:40 PM

nevermind that last one... that was dumb.you should be able to get more flow than that for a 1.5" drainpipe.

Scuba_Dave · 04/17/2006, 07:26 PM

"You size a return pump by display size, not drain pipe size."

"Since flow depends on pi x square of the radius, increasing the diameter by 50% would increase the flow by ~2.25

If flow through a 1" drain is 660 gph then flow through a 1.5" drain should be ~2.25 x660=1485 gph"

Right on the money. The size pump you want is based upon the size of your tank, how much your returns can handle, how much flow you want, and how much flow your sump can handle without having bubbles everywhere, and what type of coarls you will have, and bare-bottom tank or DSB?

Lot's of variables. I have a 125g with dual 1.5" drains, I;m running an Iwaki 70 pushing just over 1400gph by my estimate.
Two drains for security...due to algae growth BOTH drains were slowly getting clogged. Better to have too much drain capacity...then too little

04/16/2006, 11:05 AM	#1
pastelball Registered Member Join Date: Dec 2004 Location: Galloway, Ohio Posts: 592	Pump size? What size pump do you think would be good for 1 1/2" drain? I might stick with the Mag drive line as you can find them online for a decent price. The return will only be about 4 to 5 ft. Any other suggestions would be great.

04/16/2006, 09:02 PM	#2
unit91 Registered Member Join Date: Feb 2006 Location: BC Posts: 52	well, 600pgh is the max flowthru for my 1" drain... so you can basically calculate it... 600gph x 1.5 = 900pgh... so if you want to stick with mag...(god knows why?!) I'd guess you need a mag 9... although if I were you, I'd MUCH sooner opt for one of the vastly superior brands: ie, eheim 1262, poseidon PS3 These will run many years longer and a million times more quiet. __________________ 72gal bowfront fowlr w/approx 40lbs fiji LR + 50lbs LS, 20gal sump. Rena XP3 canister, Remora skimmer 1-Picasso trigger 1-Coral Beauty 1-Diadema Dottyback 1-Six Line Wrasse 1-Percula Clown Current Tank Info: 72gal bowfront w/overflow, fowlr

04/16/2006, 09:06 PM	#3
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	Assuming you are posting about a return pump, size it to 3 - 5X display size after headloss. For example, a 100G tank should have 300 - 500 GPH return flow after headloss. __________________ - Scott

04/16/2006, 09:42 PM	#5
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	You size a return pump by display size, not drain pipe size. and... *To Reef Central* __________________ - Scott

04/16/2006, 10:40 PM	#7
unit91 Registered Member Join Date: Feb 2006 Location: BC Posts: 52	nevermind that last one... that was dumb.you should be able to get more flow than that for a 1.5" drainpipe. __________________ 72gal bowfront fowlr w/approx 40lbs fiji LR + 50lbs LS, 20gal sump. Rena XP3 canister, Remora skimmer 1-Picasso trigger 1-Coral Beauty 1-Diadema Dottyback 1-Six Line Wrasse 1-Percula Clown Current Tank Info: 72gal bowfront w/overflow, fowlr

04/16/2006, 09:31 PM	#4
Jaygar Registered Member Join Date: Jan 2003 Location: SF Bay Area-California Posts: 26	Since flow depends on pi x square of the radius, increasing the diameter by 50% would increase the flow by ~2.25 If flow through a 1" drain is 660 gph then flow through a 1.5" drain should be ~2.25 x660=1485 gph So wouldn't we be looking for a pump that will deliver 1485 gph adjusted for head?

04/16/2006, 10:00 PM	#6
Jaygar Registered Member Join Date: Jan 2003 Location: SF Bay Area-California Posts: 26	I have no argument there. My comments were really directed at the math re flow rate vs diam.

04/17/2006, 07:26 PM	#8
Scuba_Dave EMERTXE YID Join Date: Apr 2003 Location: Asylum, South of Boston, MA Posts: 10,362	"You size a return pump by display size, not drain pipe size." "Since flow depends on pi x square of the radius, increasing the diameter by 50% would increase the flow by ~2.25 If flow through a 1" drain is 660 gph then flow through a 1.5" drain should be ~2.25 x660=1485 gph" Right on the money. The size pump you want is based upon the size of your tank, how much your returns can handle, how much flow you want, and how much flow your sump can handle without having bubbles everywhere, and what type of coarls you will have, and bare-bottom tank or DSB? Lot's of variables. I have a 125g with dual 1.5" drains, I;m running an Iwaki 70 pushing just over 1400gph by my estimate. Two drains for security...due to algae growth BOTH drains were slowly getting clogged. Better to have too much drain capacity...then too little