Are "closed loop" systems old school?

[HarlequinTusk]

I was at the most reputable LFS in town yesterday and was asking some questions about water movement in a reef tank. The guy was suggesting that unless the tank is very large, that a closed loop system was old school. He said the modern way to get the desired water movement was to use pumps like VorTech. He said that the closed loop systems are much harder to maintain than pumps that can do the same job. His logic seemed reasonable to me, but I wanted to know what others think.

I'm already leaning towards drilling the back glass on my tank to install a BeanAnimal overflow. If I was going to add closed loop water flow, I'd be drilling even more holes. If closed loop is truly old school, then I'd probably lean towards the VorTech. BTW, of course I realize that the store would like to sell me VorTech pumps. I'm not concerned about salesman motive, I'm just trying to find out what's truly best for my tank.

Your thoughts?

 

[ThreeMoneyJ]

I do not have a closed loop and dont think I ever would. I would prefer to have fewer points of failure for my tank (leaks etc) and the ability to move/aim circulation depending on my tanks needs.

 

[anbosu]

I think that's a pretty accurate viewpoint. In theory closed loop systems are awesome but in reality they tend to have frequent issues.

 

[amj991]

Love my closed loop. Tank looks clean, no wires and big bulky power heads in tank.

I have a blowhole 3 speed pump so I can adjust the flow real easy.

 

[mhsmith]

I am planning a closed loop with 2 pumps feeding the display tank and no power heads in the tank. That is my plan. I will have 6 drilled holes in the back of the tank with 3 on the cross braces in the front. I hope my plan doesn't have a big problem, I am currently in planning stages, and getting ready to order a custom tank.

 

[DavidinGA]

I do not have a closed loop and dont think I ever would. I would prefer to have fewer points of failure for my tank (leaks etc) and the ability to move/aim circulation depending on my tanks needs.

This.

 

[mc-cro]

I was going to use a closed loop on my last tank build, as I had used them before.

But, once I added up the cost of a good, quiet pump, all the plumbing, the oceans motion I wanted, it was the same price as a couple of used Vortechs.

Vortechs will never leak, never drain the tank, and if I dont like where they are at, I can move them. try moving your closed loop.

 

[betamed]

Modern circulation pumps are great due to their controllability and efficiency.

 

[on the spot]

...The guy was suggesting that unless the tank is very large, that a closed loop system was old school...His logic seemed reasonable to me, but I wanted to know what others think...

I don't know what old school means. It makes me believe the teller wants to be perceived as cutting edge, or ahead of the curve. Makes no sense to me.

Closed loops are great. I'd prefer them on smaller tanks to limit the intrusion of stuff in the tank. The larger the tank, the less obvious powerheads become. JMO.

For the record I stopped using a closed loop when I switched to the 240.

 

[mc-cro]

I don't know what old school means.

I do believe you are now old school

 

[fishpureluck]

I removed the closed loop set up from my 400. I extended the returns to the top of the tank "to prevent flooding" and used the two closed loop suction side to drain into the sump with the other over flows. The hammerhead pumps flow is so high that I got rid of the skimmer pump and plumbed it into the main pump also. Even with the skimmer plumbed in and the 8 returns, I have to dial back the flow on the pump. Everything works great, and I only need 1 pump for everything.

 

[Drae]

I think closed loops are old school. I would rather have high end powerheads like tunze 6255's or even noisy mp 60's.

 

[mhsmith]

I am sorry, I misspoke, I will not have a closed system. I will be running by system through a sump. My only closed system will be for my UV lights as I will run them from my sump to my sump.

 

[Av8bluewater]

I think the Vortechs will give better flow. It's broader instead of pointy loclines. I guess if you have enough closed loop it could be good. Vortechs do not have to be pointed. With two or more communicating tidal surges and programs like that I think are better at pulling detritus out from nicks and crannies.
Any way .. My vote is that yes closed loop is a little old school. If you have room to do a fish room and can have massive pumps moving a nice CL system I can see where that would be nice... but for the most part it's the broad flow of the vortechs. If you are thinking about cheap straight line power heads then I think CL would be better.
I big huge Reeflo dart is 3600 GPH and one tiny vortech is 3000 and that is in the tank. With the reeflo by the time it gets to several inlets it is diminished and in a pointy flow fashion that dissipates rapidly.

 

[wonrib00]

I wouldn't say they are old school either, but the idea has been around for a while. I put one in on my 120 last year with a BA. It is run by a snapper/dart. I have six outlets for the CL. I also added a MP40.

I have a bunch of smaller rock that make up a rim around the tank for the zoas to grow on. This will hide the nozzles and keep the zoas off the main rock structure so there is less competition for the SPS.

 

[HarlequinTusk]

I think that's a pretty accurate viewpoint. In theory closed loop systems are awesome but in reality they tend to have frequent issues.

What are the most common issues? Leakage? Clogged intakes/outtakes?

I know I'd be a little nervous drilling holes near the bottom of my tank when you consider the risk of a leak draining the whole tank. I'm also guessing that clogged intakes/outtakes could be difficult to get to if you've aquascaped your live rock to hide them.

 

[RocketEngineer]

What are the most common issues? Leakage? Clogged intakes/outtakes?

I know I'd be a little nervous drilling holes near the bottom of my tank when you consider the risk of a leak draining the whole tank. I'm also guessing that clogged intakes/outtakes could be difficult to get to if you've aquascaped your live rock to hide them.

What most people fail to consider is that modern propeller pumps are a much more energy efficient option.

Ignoring all the fancy options, for a straight up comparison look at a CL vs a basic propeller pump of similar rating:

Option A: One Reeflo Dart producing 3600 gph uses 165W on average and costs $315.

Option B: One Tunze 6125 producing 3150 gph uses 22W and costs $243.

So, for roughly the same flow (give or take plumbing) the CL would cost more to set up ($315 plus bulkheads & valves vs $243 and just installing it) plus it uses 7.5 TIMES the electricity. The Tunze would cost ~$20 in electricity per year depending on local rates. The CL would cost $144 per year to run. At that pace, you save enough money to buy a second Tunze in two years vs running the CL.

There are other reasons why CL have gone out of style but as far as I can determine, the economics of the setup are the single biggest factor.

HTH,

 

[ca1ore]

First of all, not sure why closed loops will have more problems than in-tank power-heads. Done properly, I cannot actually think of anything that is as close to 'set it and forget it' as a closed loop.

IMO, a closed loop and in-tank power-heads are used for different purposes, and I run both. In-tank power-heads are essential for water column flow and surge, but not particularly useful for providing directed flow behind rockwork. for example. While the Vortech pumps are awesome, and I would not run a reef tank without one, their design (inability to angle) makes them essentially incapable of giving really good flow behind a rock structure unless you have an open aquascape (which I don't like). I use a closed loop pump, with its output directed downwards behind my rockwork, to provide flow that the Vortechs cannot accomplish. OK, you could certainly drop a regular power-head behind the rock to do this as well, but that seems inelegant to me.

I would absolutely not attempt to do the job of a Vortech with a closed loop pump - won't get the same kind of broad flow, and you will burn up a whole lot of extra electricity in the bargain - but they still have their place, old school of not!

 

[cooterbrown]

My closed loop has been a night mare. Mostly the oceans motions. The top blew off last night and dumped a ton of water into the living room. So it's going in the trash. It didn't work right out of the box. The closed loop is nice though. But I think I'm going to hard plumb the pump back together without a flow device and just turn it on occasionally for crazy flow to clean the rocks and buy 2 mp40s for everyday flow

 

[ca1ore]

I know I'd be a little nervous drilling holes near the bottom of my tank when you consider the risk of a leak draining the whole tank. I'm also guessing that clogged intakes/outtakes could be difficult to get to if you've aquascaped your live rock to hide them.

Although I ran a tank with holes for a closed loop in the bottom for years without incident, I'd don't think it is a particularly good idea (both for safety and for ease of cleaning). However, to run a CL, holes drilled along the top of the back work perfectly fine. Use black PVC for both suction and return, and they are far less obtrusive than any in-tank power-head. I have just ordered a new tank, and have specified three holes along the back for potentially two closed loop pumps (in addition to two MP40s)