To closed loop, or not closed loop.... that is the question

[SChrisEV]

So I am leaning more and more toward upgrading my tank with my move. My 185 is a great tank, love the stand and set up, but I have a 13' wall in a room that will by the aquarium room... so, good candidate for an upgrade. I feel like I asked this general question when I was looking to upgrade last time, but ended up getting a used tank and did not want to drill it for a closed loop. Here I am again asking for your input, experience you've had, heard of etc.

I'm looking at a 7 or even 8 foot tank, 3 feet deep (front to back), and the idea of a closed loop system for water flow is pretty appealing. Having 4 to 8 holes in the bottom of the tank for the closed loop, is a little concerning, I guess with reef ready tanks there are usually 4 or more holes for drain and return, so is that/should that be a concern? But a leak in that area (drain/return) is usually behind a smaller overflow box so less water to deal with if there is a leak. I will not really have much under the tank, the sump will be remote behind a wall. If I ever need to deal with a leak etc. in the closed loop I'd have to drain the whole tank... So again really just looking for your input/thoughts.

Thanks in advance.

[Dan H]

It's funny how the hobby keeps changing it's mind on closed loops. It seems like now that we have controllable DC pumps, they are starting to look like decent options again... However, you have to consider that the propeller or gyre style of pumps are moving a LOT more water for less energy and less heat than a big centrifugal pump. The other big negative in my opinion on the closed loops are the added complexity of dealing with all that plumbing. I originally wanted to do a closed loop, but after researching the gyre's I went with those. Although I don't like having them hanging off the sides of my tank, they move so much water and barely use any electricity so it's kinda worth it. Plus I have them doing all sorts of fun stuff being programmed in to my Apex.

[jestep]

Tough to say, they definitely can be setup to work well but I'd be reluctant to want to mess with one failing on that size and placement of a tank. I wouldn't even know where to begin to store 400 gallons of water if you had to drain it in an emergency. IBC totes aren't exactly compact enough that I like keeping them everywhere.

I'd personally probably stick with in-tank circulation pumps. If I were designing the tank myself, I'd definitely be going with a external horizontal style overflow as well. I definitely prefer them in function and potential noise compared to durso or other vertical overflows. If done correctly, they take up zero space in the tank as well which is great for keeping a cleaner look.

[Sascha D.]

You're talking about 250-300 gallons of water and no bulkhead lasts forever. If I spring a leak in my bulkhead tonight, then I'm limited to the amount of water in my return pump chamber plus the ATO reservoir (about 40 gallons total). If you spring a leak over night then you could wake up to a Servpro commercial. J.K. Simmons says that Farmers Insurance has seen everything, but I don't want to test my insurance. On the plus side, a DC pump on a closed loops will use less electricity and save you money over the long-term. Circulation pumps aren't cheap and they're getting more expensive, so you could save $500 there as well. Having less circulation pumps would give you more natural look.

I haven't kept up with new technology in at least ten years, so I won't try and make any recommendations. I'm sure there are things you can buy or controller attachments that will help minimize risk if you want that clean, modern look a closed loop could provide. I decided to go with internal instead of an external overflow box to minimize the risk potential.

[SChrisEV]

Tough to say, they definitely can be setup to work well but I'd be reluctant to want to mess with one failing on that size and placement of a tank. I wouldn't even know where to begin to store 400 gallons of water if you had to drain it in an emergency. IBC totes aren't exactly compact enough that I like keeping them everywhere.

I'd personally probably stick with in-tank circulation pumps. If I were designing the tank myself, I'd definitely be going with a external horizontal style overflow as well. I definitely prefer them in function and potential noise compared to durso or other vertical overflows. If done correctly, they take up zero space in the tank as well which is great for keeping a cleaner look.

Yeah, I am likely going to go with the synergy overflow. Good point about the storage, it's will be just shy of 350 gallons, and unless I put in an in ground container, I will not have a place to storage that in case of emergency, or planned maintenance.

[SChrisEV]

It's funny how the hobby keeps changing it's mind on closed loops. It seems like now that we have controllable DC pumps, they are starting to look like decent options again... However, you have to consider that the propeller or gyre style of pumps are moving a LOT more water for less energy and less heat than a big centrifugal pump. The other big negative in my opinion on the closed loops are the added complexity of dealing with all that plumbing. I originally wanted to do a closed loop, but after researching the gyre's I went with those. Although I don't like having them hanging off the sides of my tank, they move so much water and barely use any electricity so it's kinda worth it. Plus I have them doing all sorts of fun stuff being programmed in to my Apex.

Yeah the DC pumps make them very interesting, The DC pumps also drastically reduce the energy cost of the pump, not sure how they compare to the in tank ones. Heat does not seem like it would be much of a thing, I run an external (not submerged) pump for my return, I have the opposite issues, my heater has actually come on this summer.

[SChrisEV]

You're talking about 250-300 gallons of water and no bulkhead lasts forever. If I spring a leak in my bulkhead tonight, then I'm limited to the amount of water in my return pump chamber plus the ATO reservoir (about 40 gallons total). If you spring a leak over night then you could wake up to a Servpro commercial. J.K. Simmons says that Farmers Insurance has seen everything, but I don't want to test my insurance. On the plus side, a DC pump on a closed loops will use less electricity and save you money over the long-term. Circulation pumps aren't cheap and they're getting more expensive, so you could save $500 there as well. Having less circulation pumps would give you more natural look.

I haven't kept up with new technology in at least ten years, so I won't try and make any recommendations. I'm sure there are things you can buy or controller attachments that will help minimize risk if you want that clean, modern look a closed loop could provide. I decided to go with internal instead of an external overflow box to minimize the risk potential.

Having less equipment in the tank is the whole idea IMHO. Yes I can be more specific with the flow etc. but having then pumps on the wall(s) is not very appealing. I'll have to put a tank under the tank in case of a major leak.

[Sascha D.]

In tank circ pumps are around 40w each and you'll need 4 of then. Do, 160w for 24hr * your energy cost will give you a per day rate.

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[+FluxCapacitor]

Can someone explain what a "closed loop" system is to noobs like me? I re-read the first post a few times to try to understand what was being talked about but I still feel lost. It sounds to me like water is being moved external to the tank and back into the tank.... draining out of holes in the bottom and returning via pumps to the top? Am I way off? What are the "alternatives" that people use to this type of system?

[jestep]

Can someone explain what a "closed loop" system is to noobs like me? I re-read the first post a few times to try to understand what was being talked about but I still feel lost. It sounds to me like water is being moved external to the tank and back into the tank.... draining out of holes in the bottom and returning via pumps to the top? Am I way off? What are the "alternatives" that people use to this type of system?

Basically inline pump(s) also perform the function of in-tank water movement, they are plumbed directly from a drain to the pump inlet, and then from the pump outlet, back to the tank for movement. Separate overflows and returns are utilized for keeping a sump. It eliminates the need for in-tank pumps like jebaos or vortechs or gyres, for a cleaner look in the tank, but at the expense of a significant increase in complexity and potential for leaks due to the number of bulkheads and plumbing overall being used.

[JasReef]

I have a closed loop at the moment but will not be using it on the new tank. They just add way more complexity in terms of plumbing. Is it nice not to see equipment, sure, but you add a lot more equipment behind the scenes to make up for it. And if you hide the nozzles in rock work then it is a pain to adjust as your tank grows and new flow patterns are needed. I love the idea but not the execution. I use the Vectra L1 and an oceans motion for randomness now but it just wasn't hitting everyplace, so I put in a Gyre 150.

They gyre 150 is awesome. It moves so much water. In a week or so they are coming out with a Gyre 280 rated a t 6000gph. I plan on using two of those. I don't like the integration with the apex, it is to sloppy for me and I don't think you get the full potential with it, but the new Gyres are coming with an improved controller and I will use that to sync the two.

http://www.coralvue.com/maxspect-xf250-gyre-pump-2377

[JasReef]

Heres some more complex examples.

I would much rather plug in 2 Gyre 280's and be done with it.

[SChrisEV]

Can someone explain what a "closed loop" system is to noobs like me? I re-read the first post a few times to try to understand what was being talked about but I still feel lost. It sounds to me like water is being moved external to the tank and back into the tank.... draining out of holes in the bottom and returning via pumps to the top? Am I way off? What are the "alternatives" that people use to this type of system?

Sorry Flux, the description that jestep gave and pics that JasReef provided are good. In my specific case, I'd have a "drain" or inlet from the back of the tank (larger hole with bulkhead), with an external pump basically pulling wanted from that hole, and return it back to holes w/bulkheads on the underside of the tank, with something like an oceans motion device and a DC pump to alternate the flow through the returns with varying flow rates.

[SChrisEV]

I have a closed loop at the moment but will not be using it on the new tank. They just add way more complexity in terms of plumbing. Is it nice not to see equipment, sure, but you add a lot more equipment behind the scenes to make up for it. And if you hide the nozzles in rock work then it is a pain to adjust as your tank grows and new flow patterns are needed. I love the idea but not the execution. I use the Vectra L1 and an oceans motion for randomness now but it just wasn't hitting everyplace, so I put in a Gyre 150.

They gyre 150 is awesome. It moves so much water. In a week or so they are coming out with a Gyre 280 rated a t 6000gph. I plan on using two of those. I don't like the integration with the apex, it is to sloppy for me and I don't think you get the full potential with it, but the new Gyres are coming with an improved controller and I will use that to sync the two.

http://www.coralvue.com/maxspect-xf250-gyre-pump-2377

Thanks for the feedback, Good to hear some specific experience. I was looking at the oceans motion with maybe a variable rate DC pump, and yes I do understand that with this type of set up my rock work, and coral placement would be geared around the flow.

[SChrisEV]

The feedback has been good, I think most of it is "talking me out" of the decision to do a closed loop system. Not that most of the input is something that I have not thought about, but it's good to get others perspective. The idea of needing to drain the tank if there is a failing bulkhead is not very appealing at all. I think maybe I forgot this big tank, do a 20g long, and put it on a closed loop! I mean I can drain 20g into a container to fix a leak.

[Neon Reefer]

But a leak in that area (drain/return) is usually behind a smaller overflow box so less water to deal with if there is a leak. I will not really have much under the tank, the sump will be remote behind a wall. If I ever need to deal with a leak etc. in the closed loop I'd have to drain the whole tank... So again really just looking for your input/thoughts.

Thanks in advance.

With a DC pump external, there is no reason why you cannot set up a closed loop system protected by the same overflow(s) that protect your return water for filtration. Two corner overflows set up with three holes each one for return and one for drain to sump. Another hole for closed loop to external pump and return to back of tank. You can place them at any level and if you ever have a need to lower tank level a bit thread in a siphon break pipe above the surface. Only other issue is as someone else mentioned. The return bulkhead could began leaking and you would need to lower the level of the tank to below its level to work on it.

If you did a coast to coast overflow you could put everything in the overflow drain to tank X2 return X2 drain to closed loop pump and return from closed loop X how ever many you want.

[JasReef]

I did a lot of research on the closed loop before I choose it. I read a lot about people being concerned with the bulkhead leaking but never found an example of someone who had to do it. I feel like that is one of those things that gets passed around by people who never experienced it or even used a closed loop and then it becomes "law". If you want the complexity that comes with it go for it but the last thing I would worry about are bulkheads.

Here is a good video layout on a big tank. 800g from vivid.

[SChrisEV]

I did a lot of research on the closed loop before I choose it. I read a lot about people being concerned with the bulkhead leaking but never found an example of someone who had to do it. I feel like that is one of those things that gets passed around by people who never experienced it or even used a closed loop and then it becomes "law". If you want the complexity that comes with it go for it but the last thing I would worry about are bulkheads.

Here is a good video layout on a big tank. 800g from vivid.

Yeah, I've looked at that a few times. It's a great video.

[Entropy]

The scale is obviously smaller than what you are talking about, but maybe?

http://www.melevsreef.com/node/691

[+FluxCapacitor]

Wow, that is complicated plumbing and what I envisioned was being talked about.

Are you saying that there are pumps between pumps plumped inline? That sounds a little odd if so because I could see flow restriction problems if this wasn't very well planned out.

Is the "only" benefit that it provides a cleaner look within the tank?

[jestep]

I think those are oscillators for wave making and not pumps, unless I'm missing something. The benefit to running pumps in series is to overcome excessive head loss such as trying to pump an extremely high vertical distance. For the same size pumps, the flow rate slightly increases but the vertical distance the pumps can achieve is close to doubled, not quite because of other losses due to friction and the pumps not being 100% efficient.

In something planned this well, it would be a big miscalculation to have to run anything in series.

[SChrisEV]

The scale is obviously smaller than what you are talking about, but maybe?

http://www.melevsreef.com/node/691

I've done a LOT of googling in the past, and I did see this, there was also a guy, can't find the link ATM but he did similar with the plumbing run under the sand bed, also interesting, but seems like more maintenance in the end. Also, might as well just use on wall pumps.

[SChrisEV]

Wow, that is complicated plumbing and what I envisioned was being talked about.

Are you saying that there are pumps between pumps plumped inline? That sounds a little odd if so because I could see flow restriction problems if this wasn't very well planned out.

Is the "only" benefit that it provides a cleaner look within the tank?

I would not be doing "pumps between pumps". One pump would pull water from the tank and then return it through multiple returns.