Mag 9.5 enough for sump return?

[mkreef]

Hey everyone,

I recently purchased a 120 gal RR Tank. It has two corner build-in overflows. Each has a 1" bulkhead for supply and a 3/4" bulkhead return. The return pump which I am going to use is a Mag 9.5. Is this enough to drive both returns if the main return is T-ed?

The sump is a 30gal breeder which I am going to install baffles for skimmer/fuge/return well sections. So the sumps return well will be on a far side of the tank. I am going to install ball valves on the supply lines to the sump, so the flow in the sump can be adjusted. Also, I have two Koralia 3's for in-tank flow, so I'm not really worried about that.

Maybe, Im just thinking too much about this... Your thoughts?

 

[TheGuyFromNJ]

I have a mag 9 on my 90, but turned back to about 75%. Also you should consider installing a ball vale on the return to the display instead of the inflow to the sump, the amount flowing into the display will determine the flow in the sump, w/o the worry of an overflow should something gets lodged into your valve.

There is a head loss calculator on RC if you care to use it. (not sure if links to other sites is allowed)

 

[JohnS_323]

I don't think a Mag 9.5 will be enough for your 120. When we were running our 120 (same setup as yours), we were using a Mag 12 with a Mag 18 impeller in it. The upgraded impeller made it somewhere around a "Mag 15" and it was just about perfect. We didn't have to do anything to restrict the flow and the overflows kept up with no problem.

 

[Hawkeye]

It depends on what kind of skimmer you'll be running. Ideally the return pump should not pump water back to the tank faster than the skimmer can process in the sump.

 

[sgarron]

I ran a Mag 9.5 on my 180. After a little reearch I found that 3 - 5 times your total volume is what you want going through your sump.

 

[stcreef]

Mags arent pressure rated. So every foot of head on them they reduce their output significantly. I have an AGA 120 RR sitting on a 40inch stand. Using a mag18, by the time it lifts the water all the way to the top of the tank through a T and 2 90's, I only see about 1100gph. The AGA overflows handle it very well.

 

[mkreef]

Thanks for all the replies.

I have a mag 9 on my 90, but turned back to about 75%. Also you should consider installing a ball vale on the return to the display instead of the inflow to the sump, the amount flowing into the display will determine the flow in the sump, w/o the worry of an overflow should something gets lodged into your valve.

Joe, I will be installing ball valves/unions on all lines (2 supplies, 2 returns) for adjustment and maintenance. On my 75, I have an HOB overflow (the main debate point with my wife to get the a RR tank because of the need for an aqualifter and it failing ). I restrict the supply to eliminate the gurgling, and adjust just enough to equalize with the return pump at 100%. The risk of flood is negated with the size of the return well built into the sump. The return well should only contain the volume of water that the display tank can hold if the overflow is blocked. Since I custom make my sumps, I know how large to make the well.

The only consideration is to direct the skimmer output into its own chamber, not the next chamber (fuge). Thats so if there is a problem, the skimmer chamber will just recycle itself, and it will not pump its chamber water into the return well. Before the calls for skimmer blasphemy are thrown because the skimmer will skim semi-skimmed water, I would like to ask "Isn't that what skimmers with a recirc-pumps do?"

It depends on what kind of skimmer you'll be running. Ideally the return pump should not pump water back to the tank faster than the skimmer can process in the sump.

The Skimmer which I will be transfering over is a AquaC Ev120 running with a Mag 7 (mag 5 recommended). Its the Model 1 version with the outlet low on the side. The newer versions have it high on the front. But hey, I got it used for $50 (instead of $350 new) and it works just as well.

I don't agree totally with "Ideally the return pump should not pump water back to the tank faster than the skimmer can process in the sump.". The skimmer is not the only form of filtration in my sump. Filter socks, cheato, live rock/sand, and a bag of carbon just for S&Gs. All the water in the system will be "skimmed" at some point.

Mags arent pressure rated. So every foot of head on them they reduce their output significantly. I have an AGA 120 RR sitting on a 40inch stand. Using a mag18, by the time it lifts the water all the way to the top of the tank through a T and 2 90's, I only see about 1100gph. The AGA overflows handle it very well.

This is what I am concerned about. The head loss with the tank & stand height, the T and 90's (because of the left/right returns). All that put together with a 9.5 would see a net flow of ~400-600 gph guestimation... The other consideration is only plumb one of the returns to increase the flow into the tank.

But then I will be spending more (in plumbing upgrades) in the long run by trying to spend less (by not sucking it up and buying the right pump and plumbing it right the first time)... The paradox of this hobby

 

[Patriot76]

I ran a Mag 9.5 on my 180. After a little reearch I found that 3 - 5 times your total volume is what you want going through your sump.

i too use a mag 9.5 on my 180g, works fine for me. mag-18 on my skimmer & mag-7 on fug.

 

[Hawkeye]

The Skimmer which I will be transfering over is a AquaC Ev120 running with a Mag 7 (mag 5 recommended). Its the Model 1 version with the outlet low on the side. The newer versions have it high on the front. But hey, I got it used for $50 (instead of $350 new) and it works just as well.

I don't agree totally with "Ideally the return pump should not pump water back to the tank faster than the skimmer can process in the sump.". The skimmer is not the only form of filtration in my sump. Filter socks, cheato, live rock/sand, and a bag of carbon just for S&Gs. All the water in the system will be "skimmed" at some point.

Valid point. Given the choice between an underpowered skimmer (vs the return) and having an over powered skimmer - I would choose the latter. Only because no matter how hard I try - my initial idea of the "bioload" in my tank always gets bigger than I planned (oh those dastardly sales) ;D Plus for me - I really hope to keep the amount of LR and LS minimal.

Good luck! I liked the ev120 when I had it on my 55 (was hoping to upgrade)... It's a bit sensitive though - especially if you plan on putting your hands in the tank. Once you get it tuned in - it should run fine - especially for $50.

 

[ds4x4]

I have an AGA 120 RR sitting on a 40inch stand. Using a mag18, by the time it lifts the water all the way to the top of the tank through a T and 2 90's, I only see about 1100gph. The AGA overflows handle it very well.

made up my mind thanks...

especially if you plan on putting your hands in the tank. Once you get it tuned in

hopefully not all skimmers... especially when i put my face in the tank to reach the 30" bottom.. :rofl: