GPH In Sump

[colin779]

So on my 90 I currently run a 750gph return pump, the sump is a 29 gallon tank, probably about half full. My question is would I be better off with a lower gph return pump (i have a 500gph pump laying around). My skimmer is a SWC 160 cone. Not sure if it really does matter how fast the water goes past it since the skimmer is always going to pump the same amount of water. That would lower the water level on the overflow teeth as well which would help them skim stuff out of the water column better and get it down to the skimmer.

 

[IPisces]

Seems to me like you would want your tank water circulating thru the sump as often as possible. I would like to have mine run a little faster. I think the water seems kinda stagnant in the sump. On my 90, I am using an eheim 1250 pump rated at 320gph and am probably only doing 200 gph with head loss. If your overflow and sump can handle the flow, its pretty much personal preference. Mine would be somewhere around 300-350 gph with head loss.

 

[ReefGeeker]

Mine is 375 with head loss. I want a larger return though something in the 800 range i think.

 

[IPisces]

Mine is 375 with head loss. I want a larger return though something in the 800 range i think.

How big is your tank? What size overflow does it have.
You can pump water in faster than the overflow can handle. Just keep that in mind.

 

[mfinn]

I may be in the minority, but I like a slower flow through my sump.
3x to 5x the tank volume through the sump.
IMO it allows more contact time in the skimmer compartment and refugium.
Also allows detritus to settle where it can be removed, less chance of skimmer micro bubbles to get back to the display.
Lower evaporation rate.
It's just what I've been doing for a long time.

 

[Krish]

I had a 75 gal with about a 30 gal sump and had 750 gph flowing through it (minus whatever head loss). Then I had a 38 gal with about a 15 gal sump with 950 gph flowing through it (minus whatever head loss). Didn't notice a difference with either system.


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[mfinn]

Then I had a 38 gal with about a 15 gal sump with 950 gph flowing through it (minus whatever head loss). Didn't notice a difference with either system.


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I bet the fish thought they were in a jacuzzi.

 

[Krish]

I bet the fish thought they were in a jacuzzi.

Nothing they love more


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[colin779]

Tomorrow after work I'll probably change out the pump and just monitor the skimmer to see if it seems to be doing more or less. I suppose I'll know something by the end of the week =)

 

[ReefGeeker]

How big is your tank? What size overflow does it have.
You can pump water in faster than the overflow can handle. Just keep that in mind.

My tank is a 90G, it has a megaflow overflow so I think Max flow is 900 gph. What do you mean you can pump it in faster than it can handle, more than 900 gph?

 

[IPisces]

My tank is a 90G, it has a megaflow overflow so I think Max flow is 900 gph. What do you mean you can pump it in faster than it can handle, more than 900 gph?

If you get a pump rated for more than the overflow can handle you will overflow the tank. So if the overflow is rated like yours for 900gph, and you put a pump on it that pumps faster than that, its going to empty your sump and overflow your tank because it cant flow out the overflow fast enough.

What I meant was to keep in mind what your overflow can handle when deciding on a return pump.

 

[ReefGeeker]

Ok that makes sense i know that but I was like wtf.

 

[mfinn]

Tomorrow after work I'll probably change out the pump and just monitor the skimmer to see if it seems to be doing more or less. I suppose I'll know something by the end of the week =)

For me it's all about the whole thing. Not just one area.
I've had tanks setup for a long time and have had to keep my wife happy. I work out of town fairly often and she has to take care of everything when I'm gone. ( sometimes months at a time). So everything I do when I set up my tanks is designed to make them bullet proof. ( bad choise of words)
One of the things I found that helped keeping things running smooth was staying well below the limits of my overflow capasity.
And that in turn had other benefits.

 

[Peppie]

For me it's all about the whole thing. Not just one area.
I've had tanks setup for a long time and have had to keep my wife happy. I work out of town fairly often and she has to take care of everything when I'm gone. ( sometimes months at a time). So everything I do when I set up my tanks is designed to make them bullet proof. ( bad choise of words)
One of the things I found that helped keeping things running smooth was staying well below the limits of my overflow capasity.
And that in turn had other benefits.

A BIG + 1
I am a huge fan of a solid plan B. And where ever possible a plan C

 

[IPisces]

For me it's all about the whole thing. Not just one area.
I've had tanks setup for a long time and have had to keep my wife happy. I work out of town fairly often and she has to take care of everything when I'm gone. ( sometimes months at a time). So everything I do when I set up my tanks is designed to make them bullet proof. ( bad choise of words)
One of the things I found that helped keeping things running smooth was staying well below the limits of my overflow capasity.
And that in turn had other benefits.

So what other benifits?

 

[colin779]

For me it's all about the whole thing. Not just one area.
I've had tanks setup for a long time and have had to keep my wife happy. I work out of town fairly often and she has to take care of everything when I'm gone. ( sometimes months at a time). So everything I do when I set up my tanks is designed to make them bullet proof. ( bad choise of words)
One of the things I found that helped keeping things running smooth was staying well below the limits of my overflow capasity.
And that in turn had other benefits.

Something about the water being at the bottom of the teeth on the overflow is soothing... What were these other benefits?

 

[mfinn]

Slower flow usually means less noise
Lower power consumption with a smaller pump
Less chance of microbubbles in the display tank
More contact time in the refugium.
Less evaporation

Those are just a few that I like

 

[dnjan]

I'm not understanding the "contact time in the refugium" comment. could you elaborate?

 

[colin779]

Slower flow usually means less noise
Lower power consumption with a smaller pump
Less chance of microbubbles in the display tank
More contact time in the refugium.
Less evaporation

Those are just a few that I like

Those all sound good to me. Evaporation has been on my list of things to try to cut down on for a while, not a big fan of huge amounts of water going into the air in my living room.

I'm not understanding the "contact time in the refugium" comment. could you elaborate?

I would guess, correct me if i'm wrong. More contact time in the refugium would mean that if the water is passing by more slowly, more things are being deposited or settling into it for the pods and whatever else may be in there to eat, versus just blowing right past and headed back into the display. Same principal is supposed to apply for skimmers as well, but for skimmers it just seems to depend on who you ask.

 

[dnjan]

For skimmers it makes no sense whatsoever (more time in the sump leading to better skimming), but slower flow in the sump for better settling of suspended solids makes sense.
Of course, there is always the problem of adequate tumbling of some types of chaeto for people who like to keep a ball of it in the sump for added nutrient absorption.