Flow Rate Through Sump ?

Swarf · 12/18/2006, 09:01 AM

Hello All,
Yes, I've searched, maybe I'm using the wrong keywords, but I'm having trouble coming up with...

What is a good rule of thumb for determining what rate of flow (gph) is desirable through the sump?

Just for the sake of argument let's assume there will be a closed loop capable of producing more than enough turnover in the tank so that you are not really dependent on the sump return(s) to obtain the total turnover rate you are shooting for.

Also assume there will be a separate refugium, so that flow through the refugium can be adjusted independently from flow through the sump.

So, it doesn't seem like you would want near stagnancy in the sump, nor water tearing through at 100 miles per hour. Where is the "happy medium" between those extremes? What factors effect how to choose the flow rate? Protein skimmer type/size?

Thanks for helping me to get a handle on this...

Specifics that may or may not be helpful to the overall discussion:

Moving from an embarassingly small FOWLR tank to a 210 gallon (72" x 24" x 29"). 2x 1.5" overflows, 2x 1" returns.
Sump will be fabricated starting with a 55gal long tank.
Refugium will be 15 gal. (yes, the embarassingly small tank).

Thanks In Advance,
Chuck

kau_cinta_ku · 12/18/2006, 09:30 AM

usually 5-10 times turn over through the sump is ideal

Swarf · 12/18/2006, 09:49 AM

Thanks for the reply Sam.

Could you expand a little about philosophy/science behind that figure? And, are you suggesting 5-10x display tank volume, or 5-10x total volume i.e. display tank + sump + refugium volume?

Just trying to understand here, so I can go about narrowing down choices for a sump return pump.

Cheers,
Chuck

jjk82901 · 12/18/2006, 09:56 AM

Try to match the flow through the sump with the rating for the skimmer, that way you can skim the total volume of water through the skimmer. probably around 600-800 gph. What skimmer are you looking to get??

kau_cinta_ku · 12/18/2006, 10:20 AM

i go by total water vol. tank+sump/fuge so a 50 gal. tank with a 25 gal sump and a 25 gal. fuge= 100 gal. so 500 gph- 1000gph should be fine.

Swarf · 12/18/2006, 10:31 AM

Quote:

Originally posted by jjk82901
Try to match the flow through the sump with the rating for the skimmer, that way you can skim the total volume of water through the skimmer. probably around 600-800 gph. What skimmer are you looking to get??

jjk82901,
I haven't picked out a skimmer yet, that issue is an entire can of worms in itself. I think I have looked at every brand and model of skimmer on the planet. After an exploratory email, a very enthusiastic guy from Orca Systems, Shan, called me on the phone. He's about gotten me sold on trying one of their products. He's prototyping something new, and supposed to send me some pics and info soon.

So, jjk82901, if what you are saying is that the flow rating for the skimmer is the main determining factor for the flow through the sump, then that sure makes a lot of sense to me. You don't want the water flowing past the skimmer before it can do it's job.

Thanks for the input.

Chuck

kau_cinta_ku · 12/18/2006, 10:35 AM

i agree with the skimmer part but you also want a skimmer rated for more than your system so that it isn't over working. most ppl like a skimmer to be rated at 1 1/2 - 2 times their system as most companies overrate their skimmers.

Swarf · 12/18/2006, 10:43 AM

Sam,
For my system I'm expecting a minimum of 250 gallons total. So using your formula I would want 1250 to 2500 GPH through the sump. I admit I'm a noob, and know nothing, but that sounds kind of high to me.

How much water is going to flow through two 1.5" overflows? Is it even going to be 2500 GPH?

Cheers,
Chuck

kau_cinta_ku · 12/18/2006, 10:49 AM

actually to me that sounds about right as you have 2 1.5" drains 1200gph is about right. is is a good calculator also.
http://reefcentral.com/calc/sump.php

Swarf · 12/18/2006, 10:52 AM

Quote:

Originally posted by kau_cinta_ku
i agree with the skimmer part but you also want a skimmer rated for more than your system so that it isn't over working. most ppl like a skimmer to be rated at 1 1/2 - 2 times their system as most companies overrate their skimmers.

Sam,
If I talk directly with the guy making the skimmer, and he offers a figure for ideal GPH through the sump, is that my best bet?

Chuck

kau_cinta_ku · 12/18/2006, 10:57 AM

honestly I have never seen a skimmer rated by flow size only tank size so I couldn't answer that. but a skimmer rated for at least 350 gal. would be a good bet however depending on your bioload you plan it could be more or less also.

Swarf · 12/18/2006, 11:37 AM

I shot Shan at Orca Systems an email, and luckily he had time to respond. He's suggesting a bare minimum of 3x turnover is required, and shooting for 800-1200 GPH would be smart. Which seems to be agreeing with the info I'm getting here.

Let the shopping for equipment continue...

12/18/2006, 09:01 AM	#1
Swarf Premium Member Join Date: Nov 2006 Location: Senoia, GA Posts: 93	Flow Rate Through Sump ? Hello All, Yes, I've searched, maybe I'm using the wrong keywords, but I'm having trouble coming up with... What is a good rule of thumb for determining what rate of flow (gph) is desirable through the sump? Just for the sake of argument let's assume there will be a closed loop capable of producing more than enough turnover in the tank so that you are not really dependent on the sump return(s) to obtain the total turnover rate you are shooting for. Also assume there will be a separate refugium, so that flow through the refugium can be adjusted independently from flow through the sump. So, it doesn't seem like you would want near stagnancy in the sump, nor water tearing through at 100 miles per hour. Where is the "happy medium" between those extremes? What factors effect how to choose the flow rate? Protein skimmer type/size? Thanks for helping me to get a handle on this... Specifics that may or may not be helpful to the overall discussion: Moving from an embarassingly small FOWLR tank to a 210 gallon (72" x 24" x 29"). 2x 1.5" overflows, 2x 1" returns. Sump will be fabricated starting with a 55gal long tank. Refugium will be 15 gal. (yes, the embarassingly small tank). Thanks In Advance, Chuck

12/18/2006, 09:30 AM	#2
kau_cinta_ku Moved On Join Date: May 2005 Location: NW Iowa Posts: 8,669	usually 5-10 times turn over through the sump is ideal

12/18/2006, 09:49 AM	#3
Swarf Premium Member Join Date: Nov 2006 Location: Senoia, GA Posts: 93	Thanks for the reply Sam. Could you expand a little about philosophy/science behind that figure? And, are you suggesting 5-10x display tank volume, or 5-10x total volume i.e. display tank + sump + refugium volume? Just trying to understand here, so I can go about narrowing down choices for a sump return pump. Cheers, Chuck

12/18/2006, 09:56 AM	#4
jjk82901 Registered Member Join Date: Jun 2006 Location: Nazareth, PA Posts: 147	Try to match the flow through the sump with the rating for the skimmer, that way you can skim the total volume of water through the skimmer. probably around 600-800 gph. What skimmer are you looking to get??

12/18/2006, 10:20 AM	#5
kau_cinta_ku Moved On Join Date: May 2005 Location: NW Iowa Posts: 8,669	i go by total water vol. tank+sump/fuge so a 50 gal. tank with a 25 gal sump and a 25 gal. fuge= 100 gal. so 500 gph- 1000gph should be fine.

12/18/2006, 10:35 AM	#7
kau_cinta_ku Moved On Join Date: May 2005 Location: NW Iowa Posts: 8,669	i agree with the skimmer part but you also want a skimmer rated for more than your system so that it isn't over working. most ppl like a skimmer to be rated at 1 1/2 - 2 times their system as most companies overrate their skimmers.

12/18/2006, 10:43 AM	#8
Swarf Premium Member Join Date: Nov 2006 Location: Senoia, GA Posts: 93	Sam, For my system I'm expecting a minimum of 250 gallons total. So using your formula I would want 1250 to 2500 GPH through the sump. I admit I'm a noob, and know nothing, but that sounds kind of high to me. How much water is going to flow through two 1.5" overflows? Is it even going to be 2500 GPH? Cheers, Chuck

12/18/2006, 10:49 AM	#9
kau_cinta_ku Moved On Join Date: May 2005 Location: NW Iowa Posts: 8,669	actually to me that sounds about right as you have 2 1.5" drains 1200gph is about right. is is a good calculator also. http://reefcentral.com/calc/sump.php

12/18/2006, 10:57 AM	#11
kau_cinta_ku Moved On Join Date: May 2005 Location: NW Iowa Posts: 8,669	honestly I have never seen a skimmer rated by flow size only tank size so I couldn't answer that. but a skimmer rated for at least 350 gal. would be a good bet however depending on your bioload you plan it could be more or less also.

12/18/2006, 11:37 AM	#12
Swarf Premium Member Join Date: Nov 2006 Location: Senoia, GA Posts: 93	I shot Shan at Orca Systems an email, and luckily he had time to respond. He's suggesting a bare minimum of 3x turnover is required, and shooting for 800-1200 GPH would be smart. Which seems to be agreeing with the info I'm getting here. Let the shopping for equipment continue...