Newbie Reefer help with water pump sizing

pmergler · 12/03/2008, 10:28 PM

Okay yes I am new...to reefing. I have done a 75 gallon freshwater for over 6 years now; but I just bought a "near" complete setup from a guy who had been doing reefing for over 17 years. It is a 125g with a 29g sump running a hang off siphon overflow box with approx. 9 linear (6" x 3") inch collection with a drain pipe of 1.25". I have read thru the newbie corner and needed some advise on water pump. The guy told me to get a pump with around 900 GPH flow...so I was looking at the Mag 9.5.

Then I looked at the overflow calculator based on GPH pump rating. I put in 950...that came out to an overflow requirement bigger then what I have. But then I noticed the rating for the Mag 9.5 is only 950 GPH at 1' away....so...I measured and from my sump to the return head is approx. 4'. So should I put into the calculator 810 (which is the 3' GPH rating for the Mag 9.5)? Or should I just run a Mag 7?

Thank you for the advice.

tufacody · 12/03/2008, 10:55 PM

A 1.25 drain can gravity feed 1500 gph. Find a pump that can handle that at least, and "T" off any excess back into the sump, calcium reactor, fuge, etc.

pmergler · 12/03/2008, 11:25 PM

Quote:

Originally posted by tufacody
A 1.25 drain can gravity feed 1500 gph. Find a pump that can handle that at least, and "T" off any excess back into the sump, calcium reactor, fuge, etc.

Wait...so that I understand. Since the 1.25" drain pipe size will drain out 1500 gph, I need to have a pump with that at least? If my pump is under the gravity drain of the 1.25" drain pipe, will eventually my overflow box go empty and break my siphon? Do I need to be targeting a pump with that rating at 3' distance verus the 1' distance? Does't the size of my overflow box linear inch restrict the amount of water that can go into the overflow collector?

I am confused because the guy said he was running an AquaVia 2600 with is rated at only 740 gph (this is what he used before it crapped out on him, which is why i am looking for one).

Paco · 12/04/2008, 07:44 AM

One of the mistakes I made early on in my reefing was thinking that I needed a bigger return pump. I ended up with noisy drains and more flow than necessary thru my sump. Probably any pump larger than 600 to 700 gph should be plenty. The exception would be where you might need to Tee it off to run other devices. If you're not doing that, you'll be well served by an Eheim 1262. Plenty of flow for what you're doing, quiet, low heat, reliable.

And to answer your question: your pump should probably be rated *below* the drain capacity of your overflow.

pmergler · 12/04/2008, 12:20 PM

Quote:

Originally posted by Paco
One of the mistakes I made early on in my reefing was thinking that I needed a bigger return pump. I ended up with noisy drains and more flow than necessary thru my sump. Probably any pump larger than 600 to 700 gph should be plenty. The exception would be where you might need to Tee it off to run other devices. If you're not doing that, you'll be well served by an Eheim 1262. Plenty of flow for what you're doing, quiet, low heat, reliable.

And to answer your question: your pump should probably be rated *below* the drain capacity of your overflow.

So this makes more since to me...I am not going to tee anything off. I thought my pump should be rated below my drain capacity, not more then....otherwise I am adding more water to the tank then I am taking out = over flow. So my single drain pipe is 1.25" which can handle up to 1500 gph....so basically I need a pump from between 600 gph to 1500 gph. Do I need to be concerned about my overflow box linear inches? I only have 9 inches (that is what she said...office reference, sorry couldn't help it

). So should that be a limiting factor for me to not go up past 800 gph (this was the max gph the overflow box calculator said I should use to meet the linear inches requirement for my overflow box)? Or will a bigger pump just mean MORE overflow...so rather then skimming the top most level of the water, I will be getting more water and not maximizing my water exchange and top skimming while just pushing more water = more noise; through my sump?

Also, I am still curious if I want to use the flow rating at 1' away or for more practical purposes; uses the flow rating at between 3'-4' away?

Thanks once again! I am learning so much and get so excited thinking about this hobby! Is it possible to become obsessed without even having a tank yet?

Paco · 12/04/2008, 01:12 PM

Yes, you should consider the flow rating at 4' of head, or more, depending on how you plan to return the water to the display tank. Any additional elbows, nozzles, valves, etc. each creates head pressure. Based on not planning to drive any additional devices from the return pump, that Eheim should be fine, or another pump w/similar flow.

pmergler · 12/04/2008, 03:22 PM

Oh great...thanks for the update on me rating at the expected head distance from pump to the tank!

12/03/2008, 10:28 PM	#1
pmergler Registered Member Join Date: Dec 2008 Location: Cincinnati, Ohio Posts: 10	Newbie Reefer help with water pump sizing Okay yes I am new...to reefing. I have done a 75 gallon freshwater for over 6 years now; but I just bought a "near" complete setup from a guy who had been doing reefing for over 17 years. It is a 125g with a 29g sump running a hang off siphon overflow box with approx. 9 linear (6" x 3") inch collection with a drain pipe of 1.25". I have read thru the newbie corner and needed some advise on water pump. The guy told me to get a pump with around 900 GPH flow...so I was looking at the Mag 9.5. Then I looked at the overflow calculator based on GPH pump rating. I put in 950...that came out to an overflow requirement bigger then what I have. But then I noticed the rating for the Mag 9.5 is only 950 GPH at 1' away....so...I measured and from my sump to the return head is approx. 4'. So should I put into the calculator 810 (which is the 3' GPH rating for the Mag 9.5)? Or should I just run a Mag 7? Thank you for the advice.

12/04/2008, 07:44 AM	#4
Paco Move Don Join Date: Sep 2008 Location: Miami, FL Posts: 1,210	One of the mistakes I made early on in my reefing was thinking that I needed a bigger return pump. I ended up with noisy drains and more flow than necessary thru my sump. Probably any pump larger than 600 to 700 gph should be plenty. The exception would be where you might need to Tee it off to run other devices. If you're not doing that, you'll be well served by an Eheim 1262. Plenty of flow for what you're doing, quiet, low heat, reliable. And to answer your question: your pump should probably be rated below the drain capacity of your overflow. __________________ Fish are nitrate factories. Remove them and watch your nitrates come down. Current Tank Info: 120 mixed reef

12/04/2008, 01:12 PM	#6
Paco Move Don Join Date: Sep 2008 Location: Miami, FL Posts: 1,210	Yes, you should consider the flow rating at 4' of head, or more, depending on how you plan to return the water to the display tank. Any additional elbows, nozzles, valves, etc. each creates head pressure. Based on not planning to drive any additional devices from the return pump, that Eheim should be fine, or another pump w/similar flow. __________________ Fish are nitrate factories. Remove them and watch your nitrates come down. Current Tank Info: 120 mixed reef

12/03/2008, 10:55 PM	#2
tufacody Registered Member Join Date: Jan 2008 Posts: 1,890	A 1.25 drain can gravity feed 1500 gph. Find a pump that can handle that at least, and "T" off any excess back into the sump, calcium reactor, fuge, etc.

12/04/2008, 03:22 PM	#7
pmergler Registered Member Join Date: Dec 2008 Location: Cincinnati, Ohio Posts: 10	Oh great...thanks for the update on me rating at the expected head distance from pump to the tank!