Closed loop still viable?

[dantimdad]

I am working on a 93 rimless cube and am deciding on flow. I used to use closed loops on my tanks but that was the dark ages before prop pumps and wave makers. Back then power heads maxed out about 400 gph and were pretty big and kinda loud. It wasn't uncommon to see a 225 with a row of 5 or 6 on each end and couple on the back.

The thing I can't stand is a bunch of equipment in a tank. One of the main benefits of a sump is reducing clutter in the display.

My thought is to go back to a closed loop with a DC controllable pump.

Oh the other thing is I don't want to spend several hundred dollars on an MP40 or 60 I just can't seem to justify it in my head.

Pros:
Only one pump to do maintenance on.
Quiet
Low power
One chord
Lower cost than multiple power heads
Hardly anything will show in the tank
A LOT of flow that is controllable

Cons:
Requires room behind tank
Drilling more holes (not reversible!)
Single pump, single point of failure
Possible leaks
Maybe more difficult to direct flow

So, let me know your thoughts!

 

[pluikens]

I've never run a closed loop system but I like the idea of it. In such a clean looking cube like you have, I think it'd be really neat to hide the CL plumbing within the rockwork so flow in the tank is originating from in between rock pieces with no pumps on the glass. If I were to go this route, I'd probably choose one of the Vectra pumps which have similar CL modes to what their Vortech pumps have (lagoonal, reef crest, gyre). In a larger and/or longer tank, I'd look into utilizing an Oceans Motions valve to get flow coming from various directions at different times or even multiple Vectras since MP60s are much more anyway. For a cube of your size, flow could be coming from all outlets at once in addition to a return line and you'd get really nice flow.

 

[Tft12]

I had planned to do something similar using a few DC pumps on a larger system. I’ve had very bad reliability issues with the Vectra L1 so I’m glad I don’t rely on them for all my flow. I’ve read a lot of others mentioning problems with the same pump, but people seem to be happy with the M1. It seems a lot people are having problems with other DC pumps also. You’ll want to do some research to find a pump that has held up over extended periods since, as you mentioned, you’ll be in a single point of failure —> disaster.

 

[ca1ore]

Just keep in mind that one of the benefits of something like the MP60 is massive, broad flow. Not sure you would be able to replicate this with a closed loop.

 

[mfinn]

I don't think the closed loop belongs in the "dark ages".
I had my 4 year old tank drilled for a closed loop when it was built. Added 5 extra holes.
It added about 4" extra to the back of the tank, which to me is a good thing.
Just about all the salt water tanks I've had over 33 years that I have pushed up tight against a wall has done at least some damage from salt.
Do the bulkheads right the first time and brace the pvc pipe with pipe clamps and you you run little risk of leaks.
The bulkheads can be plugged if no longer needed.
On my closed loop, I have 4 returns. On each is a loc-line Y, so I have flow going in 8 different directions from a single pump.
And you are right about the single point of failure, but I see that as a plus.

The closed loop doesn't have to be the only flow for a tank. There can be multiple sources.
I use a MP 40 on my 233 for flow along the front glass and front bottom.

 

[dantimdad]

Thanks for the input everyone.

I never had a closed loop leak before but it is a possibility, that's why I listed it.

I have a jebao dc pump on my pond that has been there for almost two years. It was on a friend's reef tank before that for a year. It has performed flawlessly. That would be the pump I was going to buy for a closed loop if I go that way.

 

[mcarroll]

I am working on a 93 rimless cube and am deciding on flow. I used to use closed loops on my tanks but that was the dark ages before prop pumps and wave makers. Back then power heads maxed out about 400 gph and were pretty big and kinda loud. It wasn't uncommon to see a 225 with a row of 5 or 6 on each end and couple on the back.

The thing I can't stand is a bunch of equipment in a tank. One of the main benefits of a sump is reducing clutter in the display.

My thought is to go back to a closed loop with a DC controllable pump.

Oh the other thing is I don't want to spend several hundred dollars on an MP40 or 60 I just can't seem to justify it in my head.

Pros:
Only one pump to do maintenance on.
Quiet
Low power
One chord
Lower cost than multiple power heads
Hardly anything will show in the tank
A LOT of flow that is controllable

Cons:
Requires room behind tank
Drilling more holes (not reversible!)
Single pump, single point of failure
Possible leaks
Maybe more difficult to direct flow

So, let me know your thoughts!

Yes a CL will do the job same as ever, but...

Power heads = ( CL x ∞ )

As for cost...

A tank that size could be easily flowed with a set of four little Tunze 6045's....$312 total.

(+$50 per rock if you want to hide one or more of them.)

$312 isn't much dough, and power consumption would be tiny.

Just for fun and ideas, here's a really nice 90 cube running some OLD OLD Tunze's....Stream 1's.

That tank could easily be re-done with one or more of these combo's:

• Two Turbelle® stream 6105's directly sub'd for the 6100's.
  
• Two Turbelle® stream 6105's hidden with Stream Rock's
  
• One Turbelle® stream 3 hidden behind rock structure
• One Turbelle® stream 3 "hidden" within/on the rock structure with Stream 3 Rock
• One or two pairs of Turbelle® nanostream® 6040's hidden behind the rocks
• Or several possible combinations of non-controllable, AC-pumps.

Nanostream pumps are smaller, so if that was a big deal you could re-do the options that call for the 6105's using about 2x the number of 6055's.

 

[Smite]

What did you end up doing @dantimdad? I'm planning on setting up a shallow peninsula style tank and have been considering a CL to keep as many pumps/clutter out of the tank as possible.

 

[sfin52]

@JoshH And @Fin here is another for you guys.

 

[JoshH]

What did you end up doing @dantimdad? I'm planning on setting up a shallow peninsula style tank and have been considering a CL to keep as many pumps/clutter out of the tank as possible.

Dooooooo ittttt!!! ;Smuggrin

There are a few options for a closed loop, even a couple that have no holes drilled in the tank. Depending on whether or not you want to use sand on your build will effect what type of system you can setup as well as what type of lighting and canopy if you go that route.

 

[mfinn]

Dooooooo ittttt!!! ;Smuggrin

There are a few options for a closed loop, even a couple that have no holes drilled in the tank. Depending on whether or not you want to use sand on your build will effect what type of system you can setup as well as what type of lighting and canopy if you go that route.

I once did a closed loop that was plumbed over the top style. No holes drilled.
It was a pain to prime, but once going, it rocked.

 

[Smarkow]

I have never reefed in the era without good powerheads but as I plan my next build, I have been seriously considering closed loops. As this hobby expands from a generation of “we’ve finally found a way to keep a reef alive and growing” to the “which of these ways is best?” era and now to our current “all of these ways work, here are the pros and cons of each” I expect some of the trends and practices to rise and fall in popularity.

The main reasons I am considering closed loop for my next system are:

1) Powerhead costs vs pump costs become more important as tank sizes increase

2) Availability and durability of DC/variable speed pumps can increase the variety of flow patterns provided by closed loops

3) Minimal footprint of equipment in the tank

4) Can put closed loops anywhere in the tank, not just along the sides

Happy reefing and good luck on your build!!!!

 

[dantimdad]

What did you end up doing @dantimdad? I'm planning on setting up a shallow peninsula style tank and have been considering a CL to keep as many pumps/clutter out of the tank as possible.

I am in the process of setting planning out a 240. I won't have time to drill and prep a closed loop as I have to move a 6 month old reef from another 240 to it within two weeks.

However, a customer ordered a 360 drilled for a Vectra L2 run closed loop system. He is using multiple L2 pumps and it will be awesome!

 

[JoshH]

I once did a closed loop that was plumbed over the top style. No holes drilled.
It was a pain to prime, but once going, it rocked.

If I were to do it over again I would have an AIO style wall built off the back panel with the center of it being the main overflow and either side would house a DC closed loop pump. Outlets would come out of the bottom of the back panel and run along the bottom of the tank covered in sand ofcourse but you could do a false bottom with some form of acrylic and run the pipes under that. Zero holes in the tank, the only thing you'd see is a wire coming out of each side of the overflow and the odd outlet head in the rock work.

 

[Smite]

Dooooooo ittttt!!! ;Smuggrin

There are a few options for a closed loop, even a couple that have no holes drilled in the tank. Depending on whether or not you want to use sand on your build will effect what type of system you can setup as well as what type of lighting and canopy if you go that route.

Hahah! That's my instinct as well

It's a smaller system 48x24x15" and that's part of my hesitation but I feel with smaller tanks, even mp40s start to stand out more, specially since I'd like to do a grey overflow/back wall (or frosted) to blend in with the wall of my home better. If I decide to go CL it will be drilled so I wouldn't want see any plumbing aside from some flow nozzles/drains.

It'll be an sps dominant tank but I love my leopard wrasse so I was planing on going with a sandbed. Also considering a carpet anemone towards the front. Im trying to find a thread where someone hid eductors down low in some rock islands. I'd like to put 2 towards the front pushing at an upward angle back towards the overflow.

Is it possible to completely eliminated powerheads? I'm assuming I would need atleast 2 CL systems for good movement/flow coverage and some redundancy incase of pump failure.

is it best to keep the drains higher and do you prefilter them somehow?

 

[User1]

I do not own a closed loop but wish I designed one in using a false wall or pre-drilled. I'll be doing this next time for sure. I was going to suggest using sea swirls but you mentioned rimless so not sure if you are open top or canopy. You could do a closed loop tied together with multiple sea swirls with random flow generators and be done. Swap between 90 and 45 degree elbows and get the flow.

I have something setup using my Apex and a virtual outlet. I named it tide with the following code:

OSC 000:00/360:00/360:00 Then ON

Every 6 hours it will switch on/off and based on that, code below, the power level of the Cor return pumps increase or decrease speed to give one side more or less flow. I've also removed the OSC / virtual outlet and let the Cor pumps ramp up, down, using the respected wizard which was really cool but my sumps water level wasn't stable so went back to the outlet.

In any case I am a fan of removing power heads if possible but a lot of it is the upfront design. I think flow in the display is more important than through the sump so the skimmer has more time to work. Something I've been learning about more recently than what I used to believe.

Cor 20:
Fallback ON
Set 45
If Output TideTiming = ON Then 10

Cor 15:
Fallback ON
Set 10
If Output TideTiming = ON Then 100

 

[Smarkow]

If I were to do it over again I would have an AIO style wall built off the back panel with the center of it being the main overflow and either side would house a DC closed loop pump. Outlets would come out of the bottom of the back panel and run along the bottom of the tank covered in sand ofcourse but you could do a false bottom with some form of acrylic and run the pipes under that. Zero holes in the tank, the only thing you'd see is a wire coming out of each side of the overflow and the odd outlet head in the rock work.

Very cool idea. Ever seen it done before? Not sure where I fall in the plenum or deep sand bed concepts, but I would worry about detritus getting trapped under the panel.

Thoughts on how to avoid this?

 

[ca1ore]

I have a closed loop on my 450 and it works fine. As you exceed 1” thick walls, power head options become somewhat limited. I do use MP60s as well as the closed loop. Ramping return pumps like the vectra have largely negated the need for things like flow diverters. I’m not a big fan of punching a bunch of holes in my tanks, so there’s that to consider. In the attached picture, closed loop are the three tubes outside the overflow.

 

[JoshH]

Very cool idea. Ever seen it done before? Not sure where I fall in the plenum or deep sand bed concepts, but I would worry about detritus getting trapped under the panel.

Thoughts on how to avoid this?

If you're implementing a sand bed of any kind you wouldn't need a false bottom as the sand would hide all the plumbing for you. Only in a bare bottom tank with no sand would you need either rockwork to cover the plumbing or a false bottom.

 

[pgravis]

I just ordered a tank and I really considered doing a closed loop. The tank isn’t big at all, just a slightly stretched 60 cube-but I like the clean lines of not having a powerhead in the tank. This thread is making me want to call and add a couple more holes to the back wall!