Are Closed Loop Systems Obsolete

[Brianrobb]

Hi All,

I'm planning my next build and I've got just about everything figured out except...circulation.

Is anyone using closed loop systems any more or have the new high flop prop pumps made these a thing of the past?

I like the idea of a clean looking tank without a bunch of power heads but my current tank is suffering from insufficient flow so I want to remedy that this time.

My two leading options are a closed loop system with the suction being low on the back glass or through the bottom using short pipe and screen. The CL returns will go up and over the top of the tank (plumbing covered by a canopy).

My second option is a set of 2-3 Neptune Systems WAV pumps.

Thoughts?

 

[Sk8r]

My recommendation would be a Gyre---small, fits up near the surface on a side, and sends a rolling current through the tank. I don't use it on pulse---figure it will last longer just blowing one direction---but one unit handles my 102 gallon bow quite nicely.

 

[ycnibrc]

With all the new technology in power head I have to say it's not wise to have close loop anymore. More chances to leak, cannot change flow pattern, flow is weak due to head loss and plumbing. With all the program and flow pattern of modern power head it's too good not to use it.

Sent from my SM-P900 using Tapatalk

 

[ca1ore]

Obsolete, no; out of favour, yes. They still work as well as they always did, so in that sense they are not obsolete; however, prop-based powerheads work better in most applications. If you are going to do a closed loop, put bulkheads up high in the tank, use a variable flow pump like a Vectra and upsize plumbing.

 

[marinelife]

I have a closed loop on my tank and would not be without it. That being said I have gyre pumps to create that flow my corals want.

 

[johnike]

I replaced the years old closed loop on the 240 with a Gyre.
Just love it.

 

[Ron Reefman]

I had a closed loop on my old 180g. But the tank had to be replaced and I didn't bother with a CL in the new system given the much better wavemakers and gyre. The CL is still a perfectly good system, but it doesn't hold any advantage like it used to IMHO.

 

[biecacka]

I think on some larger tanks closed loops prevail no questions. Other than that, like others have said, new technology pumps usually prevail.

Corey

 

[hkgar]

I have a 180 DT with 2 corner overflows to a sump in the basement. The return is a Iwaki 100. Is that a closed loop system?

I also have two Gyre 250 for increased flow.

 

[MobileLightning]

I have a 180 DT with 2 corner overflows to a sump in the basement. The return is a Iwaki 100. Is that a closed loop system?

I also have two Gyre 250 for increased flow.

I been out of it for a while but back in the day, a closed loop system pulled from the DT and sent directly back to the DT normally by an external pump.

Regards,
J

 

[Ron Reefman]

I have a 180 DT with 2 corner overflows to a sump in the basement. The return is a Iwaki 100. Is that a closed loop system?

I also have two Gyre 250 for increased flow.

No, it's a remote sump.

 

[d0ughb0y]

It's like saying I still churn my own butter, worked for (hundreds of) years, still works now.

 

[saf1]

With all the new technology in power head I have to say it's not wise to have close loop anymore. More chances to leak, cannot change flow pattern, flow is weak due to head loss and plumbing. With all the program and flow pattern of modern power head it's too good not to use it.

Sent from my SM-P900 using Tapatalk

Actually, you can change flow patterns - Oceans Motions is just one example. You can also use Sea Swirls with a closed loop.

It really comes down to what you are trying to achieve long term and your design goals. I do agree that some of the new DC pumps and wave makers do make things easier but those have their own baggage if truth be told. Cleaning comes to mind. Cost another. I wouldn't say one is adding more complexity than the other. Just comes down to what you are trying to do in the end.

So no, not obsolete.

 

[slief]

I run a closed loop on my system. Years back I had a few closed loop pumps. I switched all but one out for Tunze's. The one I retained is fed by an RD3 230 and setup so it exhausts under my live rock to prevent detritus from settling under the rocks. It also feeds my UV sterilizer. At night the pump slows down to conserve energy and during the day it runs at a high flow rate. When my Tunze's kick into what I call flush mode, the closed loop kicks up to a higher speed to suspend any detritus that may have settled near the rocks. The Tunze's then kick up to full speed on one side of the tank for a minute while the other side shuts off. The the other side kicks up to full side while the opposite side shuts off. This repeats a few times and the process gets all the detritus up high into the water column before the Tunze's go back into a pulse mode. Between that and my Seaswirls on my return, the detritus is sent into the overflow. It's applications like mine that I think closed loops have a benefit. That said, modern wave makes can produce more flow with less power and offer better control so that being said, closed loops aren't for everybody and I rarely advocate them.

 

[ca1ore]

With all the new technology in power head I have to say it's not wise to have close loop anymore. More chances to leak, cannot change flow pattern, flow is weak due to head loss and plumbing. With all the program and flow pattern of modern power head it's too good not to use it.

Some misconceptions here. Whether it is wise or not is dependent upon the situation. I'd argue that there certain applications where a closed loop may be appropriate. You are correct, of course, that every additional piece of plumbing is an opportunity for a leak; however, sensible installation (bulkheads high up in the tank) makes this unlikely. Closed loop has plumbing friction, but no head loss because it's closed. As long as one does not overly constrict the pump (use 'native' sized pipes), there is very little flow loss. I have a CL on my 265, and plan to also use it on my pending 400; though it's mostly because I already have the equipment. If I did not, I would probably just buy a third vortech

 

[ycnibrc]

Close loop is like vcr it's on the way to extinction. If you look at the market right now not one company are talking about close loop. Power head is so cheap and more advanced now a day not too many reefers chose close loop any more. My old tank has close loop but that was 13 years ago when tunze powehead was $600 a piece. Modern Reef tank now is going for a clean look if u look at all the sump lately.

 

[ca1ore]

Close loop is like vcr it's on the way to extinction. If you look at the market right now not one company are talking about close loop. Power head is so cheap and more advanced now a day not too many reefers chose close loop any more. My old tank has close loop but that was 13 years ago when tunze powehead was $600 a piece. Modern Reef tank now is going for a clean look if u look at all the sump lately.

No need to be defensive, was simply clearing up a few misconceptions so that the OP could make an informed decision. FWIW the 'market' tends to have bright-shiny-object syndrome, and chases what's 'in' and thus saleable; so it's not a particularly good guide to best practice frankly. A CL actually presents a cleaner look to the tank than a lot of clunky power-heads, but is inferior in overall flow and the power required to accomplish it. YMMV.

 

[ktownhero]

If you look at the market right now not one company are talking about close loop.

Actually, I believe one of Ecotech's marketing points for the Vectra is that it's a great option for a closed loop...

 

[taylor t]

IMO, it's ALL personal preference. I prefer to pay less electric bill, I can't find a closed loop pump that's even close to the "bang for buck" like the MP40 or Gyre. Closed loop (IME) is more reliable, less cleaning, more powerful, but when there's trouble, it can be a headache, depending on how it's plumbed. I have 2 closed loops drilled on my 210, I closed 1 a couple years ago, just shut off the other one after it shreaded an anemone a couple weeks ago. I prefer prop pumps myself based on water push capability and cost of long term operation, but both have their places IMO.

In 8ish years, I've never cleaned, replaced, or messed with my closed loops other than turning them on off or closing them permanently-they are basically maintenance free. I've replaced all my prop pumps multiple times, and all need constant monthly cleaning. Pro's and cons to both.

 

[jda]

They are still very effective on larger tanks when used with a OM, or the like. While gyres can move water, it is still mostly static and I would rather than half the movement in a more random way. That being said, I have opted for Tunze pumps over the last decade in combination with a wavebox and have plugged my CLs. If I got a 500G plus tank, I would probably look at CL again with a VERY large Ampmaster to feed it. Eductors are highly underrated and can really move some serious water that will make a MP40/60 or Tunze beg for mercy.