One return pump or two?

[phoenix20]

So i'm trying to decide what return pump to put on my 120g. It has two overflows, both of which are rated at 600gph -- so i'm looking for a return pump thats around 1200gph.

I was thinking about getting a submersible Mag 12 (the thought of running a external pump is kind of scary). Would it be better if I went with one pump rated at 1200gph, or should I look at putting two pumps in the sump?

Pros: If one pump died, I would still have some flow

Cons: I would guess two submersible pumps would generate more heat than just one. (I could be wrong here).

Thoughts?

 

[tim8111]

I would recommend 1 Mag 7. The point of a sump is not to rush water through, if you do this the skimmer, heaters, and other equipment will be less effective. The longer the dwell time the more efficient your equipment will be.

Thanks,
Tim

 

[chymos45]

Tim's right. Calculate your turnover based on system parameters and bio-load, not the max capacity of the drains. Many try to increase flow in the tank with their return pumps, but hurt the performance of the overall system for the reasons Tim mentions above. If you need more flow, get some PH's or a CL.

Notice I did not endorse either method, only presented the options. Don't want to wake that beast...

 

[phoenix20]

Thanks for the advise! I already have two Korila 3's that I'm planning on putting in there, so that should be enough flow for inside the tank.

 

[phoenix20]

Thanks for the insight guys. This is why ARC rocks!

 

[lawsonr81]

I'd go with one ehiem 1260 pump. Thats what I run in my 125 gallon and I've heard they are built to last.

 

[phoenix20]

Which pump is more quiet? The mag 7 or the Ehiem 1260? The Ehiem is a little bit more expensive, but I'd be happy to pay the extra cash if it was worth it.

I'm going to have the tank set up next to the TV, so a quiet pump is crucial.

 

[chymos45]

Can't speak on the Ehiem, but Mag 5, 12, and 18 are pretty quiet. I have an 18 on my 185 now (return is split between sump and fuge) and the noise I hear is from the water in the lines, not the pump.

 

[tim8111]

phoenix20;340688 wrote: Thanks for the advise! I already have two Korila 3's that I'm planning on putting in there, so that should be enough flow for inside the tank.

It depends on what you are keeping in the tank. 2 Koralia 3's at 800 gph each is not enough in a 120 in my opinion. I would double that to 3000 gph for a softy tank and atleast 6000 gph for SPS tank.

I curently run 6 maxi-jet 1200 with mods at 1600 gph each. And I am about to remove 4 to replace with the new octopus twin propeller 3000 gph powerheads. In my 180 I will have around 15000 gph if the sand can take it, we will see.

Just my opinion on flow in a tank. There are tons of ways out there, I am just relaying what works for me.

 

[lawsonr81]

ares;340712 wrote: if its used submerged, and you put a little foam padding under it, or rubber feet, or whatever. they should both be completely silent. if it were running external, then the eheim would be quieter IMO.

water makes for a darn good noise insulator though, so as long as it doesnt vibrate against the tank, shouldnt matter.

I agree. If you put padding under the pump, either one should be just as quiet. I've got my eheim 1260 running on the bare glass bottom in my living room, where my TV is, and I have almost no audible noise coming from it. The eheim's run very smooth.

 

[phoenix20]

Wow. Thats a lot of flow. How do the fish not get sucked into a whirlpool?

So I guess I could pick up another 2x Korila 3's. They're only like $45 each. I can't justify dropping $300+ on tunze...

Whats the best way to position them? Have two near the overflows, shooting towards the front of the glass, and another two on the sizes, shooting the length of the tank?

The tank is a 60"x18"x26"

 

[chymos45]

With Tim's rate of flow, it doesn't really matter. He's got to worry more about blowing the glass out of the opposite side of the tank... (I laugh only because I am jealous)

As for yours, trial and error is all I can tell you, based on rock-scaping, what type/size corals you may have, etc. Ultimate goal is random/chaotic flow with no dead zones. Putting PH's close to the overflow may be counter-productive as they will push the crud in the water colum away</em> from the overflow, rather than "hearding" it towards</em> the overflow. Many start with flow from the outside pushing in.

 

[tim8111]

Exactly, I believe in random flow and the such.

Personally, I don't think we could ever recreate the force of the ocean waves on the reef. These fish minus the tank raised ones are use to massive flow and water movement.

My 180 is a SPS/clam tank. I have 0 softies in it. Therefore my goal is to put as much flow as the sand can handle. Good thing I don't run a BB tank.

 

[chymos45]

If you were BB, I'm sure the clams would need seatbelts.