To closed loop or not?

Brew12 · Dec 8, 2016

mcarroll said:
Pushing water through at least several feet of plumbing is always going to be massively inefficient compared to running a propellor in a tank of water.

You are ignoring the fact that I will have more total flow in a 6ft long tank using a closed loop at 1000gph than I would with a powerhead on one side running 3000gph. The inefficiencies of the piping are more than made up for by the 100% reach (if set up that way) of the system and the fact that much of the flow out of a powerhead is pulled back into the powerheads suction .

Boo Team Red!

mcarroll · Dec 8, 2016

Brew12 said:
The inefficiencies of the piping are more than made up for by the 100% reach (if set up that way) of the system and the fact that much of the flow out of a powerhead is pulled back into the powerheads suction .

I'm not sure I buy that first part. Spinning a propellor in a tank of water is practically free.

Unfortunately, there is no pipe-size-upgrade that will eliminate friction altogether for a regular impeller pump PLUS it has all the same losses as the propellor pump too.

(Tunze's new Stream 3 has even improved on that last part.)

The second part you mentioned about a pump eating its own flow, you're describing a particular non-Tunze-branded flow solution. I wouldn't recommend that.

Have you seen a 6105 in action first hand, for example? My eyes went like this the first time I replaced an mp40 with a 6105 (on a 180g, 72" tank) and saw all the detritus it lifted out of the sand and rocks:

That was a single 6105 vs a single mp4, BTW.

(Did I post that Flow vs Turbulence video here already? You can see the difference in their visual demonstrations in the second half of the vid. It'd be interesting to see someone do a similar visual test on the flow from a closed loop system.)

mcarroll · Dec 8, 2016

I did not post it yet....

mcarroll · Dec 8, 2016

Flow speed is something that's rarely addressed, but that's also where the Tunze pumps have a leg up (and which you can see in their demonstrations).....the closed loop is possibly superior in this respect as well, depending how it's built. (It would not automatically be so....outlets would have to be set up right.)

Brew12 · Dec 8, 2016

mcarroll said:
I'm not sure I buy that first part. Spinning a propellor in a tank of water is practically free.

Unfortunately, there is no pipe-size-upgrade that will eliminate friction altogether for a regular impeller pump PLUS it has all the same losses as the propellor pump too. (Tunze's new Stream 3 has even improved on that last part.)

The second part you mentioned about a pump eating its own flow, you're describing a particular non-Tunze-branded flow solution. I wouldn't recommend that.

Have you seen a 6105 in action first hand, for example? My eyes went like this the first time I replaced an mp40 with a 6105 (on a 180g, 72" tank) and saw all the detritus it lifted out of the sand and rocks: That was a single 6105 vs a single mp4, BTW.

(Did I post that Flow vs Turbulence video here already? You can see the difference in their visual demonstrations in the second half of the vid. It'd be interesting to see someone do a similar visual test on the flow from a closed loop system.)

I agree and posted earlier about the down side of a closed loop being the lack of turbulent flow.
Powerheads are like motor boats in a pond tied to a pier. You will get very strong and turbulent flow right at the propeller that diminishes as it goes away from the boat.
A properly set up closed loop is like a stream where the flows throughout are fairly even except as impacted by tank structure.

I think it depends on your goals. Do you want that turbulent flow or do you want a more uniform flow?

Drakonis · Dec 8, 2016

Gettin deeper in this pond, i think that video actually helped the case for CL in regards of flow vs turbulance but power heads retain flexability in all cases.

technojunky101 · Dec 8, 2016

It's not only about moving large amounts water but type of current corals get. Want random flow or get ocd and have current changing 6 times a day to simulate hi and lo tide powerheads will always be needed.

technojunky101 · Dec 8, 2016

mcarroll · Dec 8, 2016

Brew12 said:
A properly set up closed loop is like a stream where the flows throughout are fairly even except as impacted by tank structure.

I have never seen a closed loop system set up to model a stream.

Typically it's more a like a jacuzzi with nozzels sticking out or a shower with a dozen shower heads pointing at you from a dozen directions.

The flow from a controllable Stream or Nanostream pump is an improvement on the flow of a closed loop, while having none of the downsides of a closed loop system.

(For what it's worth, I've taken care of tanks that used one or another of all three....closed loops, mp40's or Tunze pumps. Probably more tanks I've taken care of have actually had closed loops than anything else....or it might be even. Brew, you actually use my least favorite flow source of the three. Doh!

)

The problem with the closed loop in that comparison isn't so much the flow – although the flow is challenging – it's that they have all those other problems too.

Brew12 · Dec 8, 2016

mcarroll said:
Brew, you actually use my least favorite flow source of the three. Doh!

I know.

With 2 MP40's on a 6ft tank I could never grow SPS's in the middle. My flow there is terrible. Fortunately, I set up my rockscape so that I can't really put any SPS's there so it works for now.

I've thought about changing them out to Tunze's because I love their flow patterns but I have other issues with my current tank. My system is on a replacement schedule at this point because of other things I don't like about it. As long as life doesn't throw too many curve balls the 120g will be replaced by a 180g wide. So I am holding off on any changes until then. And I am strongly considering a closed loop with several small powerheads but have plenty of time before those decisions are made.

Upstartreefer · Dec 8, 2016

To the question of closed loops and the downsides to them. Has anyone ever ran a closed loop with 2 L1 Ecotech pumps?

I've called Ecotech and they said with Ecotech live both pumps can be run just like a vertex and with that you can slow down one pump speed up another have lagoons turbulent flow or any other flow that the Ecotech has preprogrammed. Right now in my mind thinking about it I would have 3 returns off each pump two going to the side one going to the back. Another question I would have @Brew12 is can you add the two sections going to your pumps for some kind of linear flow since I'll be pulling water into it creating a flow in the tank as well?

Brew12 · Dec 8, 2016

Upstartreefer said:
To the question of closed loops and the downsides to them. Has anyone ever ran a closed loop with 2 L1 Ecotech pumps?

I've called Ecotech and they said with Ecotech live both pumps can be run just like a vertex and with that you can slow down one pump speed up another have lagoons turbulent flow or any other flow that the Ecotech has preprogrammed. Right now in my mind thinking about it I would have 3 returns off each pump two going to the side one going to the back. Another question I would have @Brew12 is can you add the two sections going to your pumps for some kind of linear flow since I'll be pulling water into it creating a flow in the tank as well?

Yes, you would have no problems going with 2 suctions. I think that would actually be wise. If I decide to go with a closed loop I would do it much differently than I have ever actually seen. I wouldn't discharge through nozzles at all. I would create a discharge header using furniture grade PVC with holes drilled in it across the length. I would do at least 3 suctions on the other end of the tank. It would work like a gyre on steroids.

mcarroll · Dec 8, 2016

Brew12 said:
Yes, you would have no problems going with 2 suctions. I think that would actually be wise. If I decide to go with a closed loop I would do it much differently than I have ever actually seen. I wouldn't discharge through nozzles at all. I would create a discharge header using furniture grade PVC with holes drilled in it across the length. I would do at least 3 suctions on the other end of the tank. It would work like a gyre on steroids.

You're definitely on the right track if you go that route! PM me if you want a second head involved in planning...I may not be a fan, but that doesn't mean I won't help!

Brew12 · Dec 8, 2016

mcarroll said:
You're definitely on the right track if you go that route! PM me if you want a second head involved in planning...I may not be a fan, but that doesn't mean I won't help!

lol Thanks! I appreciate that! Still want to learn more with my current setup before I start getting into the serious plans with the new setup.

So many ways to be successful in this hobby. It's amazing!

I'm still most in awe of those sumpless systems with only a heater, powerhead, lights, and HOB skimmer. How good do your husbandry skills need to be to pull that off?

DeniseAndy · Dec 8, 2016

I tried a closed loop with an ocean motions for altering pattern and failed miserably. The ocean motions just kept getting jammed up with sand or any tiny thing. My husband hated the noise too.

However, if I had the knowledge that my system would be in the basement (like it is now), I would have just set it up differently with two or three pumps running the flow and pattern.

The only down side of closed loop, is it is generally set once installed. I like my tunzes as I have changed animals kept and the powerheads allow me to change with those animals needs.

justingraham · Dec 8, 2016

That tunze looks like the death star inside a tank not for me

And about the l1 @locito277 uses them on a closed loop I believe if he doesn't reply look up 720 Miami build

Upstartreefer · Dec 8, 2016

@Brew12 I didn't think of that kind of setup but it sounds like it would be awesome count me in on that too I would love see how it works out.

Brew12 · Dec 8, 2016

Upstartreefer said:
@Brew12 I didn't think of that kind of setup but it sounds like it would be awesome count me in on that too I would love see how it works out.

Well, unless something changes my mind, I'm a year out!

I just like the idea of maintaining a constant gyre flow that I can ramp up and down. Using 2 mirroring systems you can mimic tidal flows. And if you use them at the same time you can get the streams to collide and really mix things up.

Since flow would be nearly uniform you wouldn't have to worry about not putting coral directly in front of a powerhead or nozzle. No dead spots in the middle of the tank. Seems like a great way to do it to me.

Upstartreefer · Dec 8, 2016

mcarroll · Dec 8, 2016

justingraham said:
That tunze looks like the death star inside a tank not for me

You don't have to mount the powerheads like they're on display, man!

I mean you can, but that's really a Vortech thing. ("Hey look at me hanging off the side of the aquarium. Me! Me! Me! Right in the middle of the glass!)

Some people actually hide Tunze pumps behind rocks and such, or even inside one of Tunze's ceramic covers to masquerade as live rock!

I mean you can even mount them on the front glass of the tank and they face away from you, so the only thing you really see is a small black disk.

Nothing remotely similar is possible with the big "V". It's all "Look at me! Look at me!"