...are closed loops becoming obsolete?

[143MPCo]

This is just a thought but what if you had a pump that was installed inside of the overflow box with the return line pointing out of a hole made into the overflow. That way you would have a great deal of flow and the only thing you could see would be the cord.

On a small system that might not be a problem and could work nicely but, on bigger systems like the one in the video (hope Dave doesn't mind me sharing his video) below it would be impractical and would probably not meet the flow requirements needed..

 

[Paul Carpenter]

This is just a thought but what if you had a pump that was installed inside of the overflow box with the return line pointing out of a hole made into the overflow. That way you would have a great deal of flow and the only thing you could see would be the cord.

Understood but maybe when you turn off the main pump and forget to turn off the loop pump, it would run dry. Also, a maspect Gyre magnet can get wet. Put the gyre on the outside of overflow box in the tank with magnet inside! Powerheads give you a bit more flexibility of placement in the tank when you move corals or change the rock scape. Finally, powerheads are getting better and better. The DC ones are wonderful. There is not much effort in the hobby improving loops! Good luck! Planning is half the fun.
Finally, my return water from the sump is similar to a loop. I have 6 return lines coming from above the tank, each with valves to control flow and I can change direction easily with those black flex things,
I forgot their name. .

 

[chill86]

That's how I have my 60 cube done. 1 return split to 4 nozzles of loc-line. Every time I plan a build I always try to make things as simple as possible. The more pieces you have in the system, the greater the opportunity for a certain implement to fail. I went for the cube because it's simple design, which only needs one light and 1 return pump.
I do know that on the really big tanks the magnets on the power heads are not strong enough to cope with the thickness of the glass/acrylic.

 

[Paul Carpenter]

That's how I have my 60 cube done. 1 return split to 4 nozzles of loc-line. Every time I plan a build I always try to make things as simple as possible. The more pieces you have in the system, the greater the opportunity for a certain implement to fail. I went for the cube because it's simple design, which only needs one light and 1 return pump.
I do know that on the really big tanks the magnets on the power heads are not strong enough to cope with the thickness of the glass/acrylic.

My tank is 3/4 acrylic and no magnet issues at all. Maxispect Gyre does sell a stronger magnet for 1 inch. Overflow boxes are rarely over 1/2 inch. Simple is best. never put holes in a tank more than 2-3 inches below high water. Bottom holes are ridiculous in my opinion. recipe for disaster.

 

[ballroomdude]

I just did the calculations for a build I'm putting together. 36000 gph total flow.

If I ran closed loop it would look like this....WITHOUT buying the plumbing bits...

Pricing per month:
Return pump: tiger shark $93
Skimmer pump: dart $14
Closed loop pumps: manta ray x4 $270
2x gyre 150s: $9

Total cost per month: $386 or $4632 per year!!!!!

Cost with DC pumps

Per month:

Return: 2x vectra l1s: $22
Skimmer: 1x vectra L1 $11
Flow: ecodrift 20s x4 $21
2x gyre 150s: $9

Total cost is $63 per month or $756 per year.

Savings of $3876 per year for a huge amount of water flow.

It would cost me 6x as much per year to run a closed loop system on my 600 gallon tank. I can't ignore that.

 

[143MPCo]

Total cost per month: $386 or $4632 per year!!!!!

Really puts things into perspective, doesn't it?

 

[ballroomdude]

Exactly!!!

 

[gcarroll]

IMO, you cannot compare propeller pumps to close loops directly. They can’t simply be compared gph for gph. 4000 gph coming out of a prop pump is in no way comparable to 4000 gph coming out of a 1 ½” PVC pipe. Apples and oranges!


Arguments can easily be made for both methods being better choices as each system is different. When you start adding things like educators and penductors on the closed loop outlets, the added head pressure will drop wattage considerably and the increased output can be monstrous. Adding devices like Sea Swirls can add another dimension allowing you to get full tank water movement with even less flow.


I truly think the argument is much more complicated that this discussion is making it out to be.

 

[ballroomdude]

I agree. However.....if taken from the perspective that I want to keep it simple and as budget friendly as possible the cost savings on a yearly basis (for me) is hard to overcome in my mind.

 

[IronVulture]

No reason you couldn't run a closed loop with dc pumps like the L1

 

[ballroomdude]

I'll see if I can calculate again later using a closed loop with eductors just as another idea.

 

[143MPCo]

No reason you couldn't run a closed loop with dc pumps like the L1

You can, as it was noted early in this thread but, the flow on the L1's are less and should also be taken into considerations.

 

[143MPCo]

I truly think the argument is much more complicated that this discussion is making it out to be.

keep in mind the thread started as an energy usage discussion, and the notion of using a DC pump in a CL system was simply a method of energy conservation.

 

[chill86]

+1

 

[JasReef]

I plan on running a closed loop with an L1 and an oceans motion. I think the programability of the L1 with the randomness of the oceans motion will create some great and different flow patterns throughout the day. I am keeping the pump as high as possible to prevent head loss. The tank is a 160 gallon. I should have this wet soon.

Also I have not drilled the hole for the return on the L1 in this pic.

Disregard the returns from sump as they have changed, chiefly the one labled return 2 is gone.

 

[gcarroll]

keep in mind the thread started as an energy usage discussion, and the notion of using a DC pump in a CL system was simply a method of energy conservation.

I completely understand the discussion's roots. What complicates things is your choice of pumps for the comparison. You just don't choose a pressure rated pump for a closed loop when you remotely care about energy efficiency. Coming from Southern California, I have a lot of experience with energy efficiency as anyone with a 200+g reef tank here is likely paying upwards of $.32 - .43 per kWh. I went from closed loop to Tunze propellor pumps 12 years ago when we did not nearly have the energy efficient pump choices that we have today.

We have already established that the head pressure on a closed loop is minimal and relegated to just the elbows in the plumbing. That being said there is absolutely no reason to choose a Hammerhead Gold or Barracuda Gold. A Super Dart Gold is more than sufficient and will get you 4200 gph for 145w. With that change alone we have dropped the usage 100w.

Where the comparison gets sticky is here. we are comparing this pump to a single Ecodrift 20.0 that puts out 5000 gph at 60w. You can't compare the 4200 gph of a dart to the 5000 gph to the Ecodrift. Imagine a 1 1/2" return directly in a 200g aquarium. Flow would be insanely chaotic. But that's not the case with the Ecodrift even though it has more GPH. This is due to the velocity of the water movement. Since running a 1 1/2" inlet straight from the Dart is not realistic we split the flow into two smaller 1 1/4" pipes. This is still a ton of flow. So to get a better comparison, you get a second Ecodrift 20.0 and now you are at 120w.

At this point you are probably saying, "but the controllable Ecodrifts can run at different speeds and that will on average cut power usage to 40w per pump. You could then swap the Dart for a Vectra L1 and you also have the ability to pulse and decrease the average wattage. In the end, the Ecodrifts/or other propellor pumps are still the better choice for energy efficiency, however the difference in not nearly as drastic as your math has shown.

 

[zach_discus]

I'm currently setting up a 240 using 2 Reeflo Super Dart Golds. Mine will each run 6 hrs at a time with 15-30 min overlap. My returns are arrayed to get a gyre going around the perimeter of the tank.

My sump return is a Jecob DCT12000 with two Loc-line returns. Last but not least is two Jebao RW-15s set to surge for a little randomness action.

Eventually I have it set up to switch the SDGs with rather Wavelines or Deepsea DC pumps.

Will say plumbing two individual closed loop under 1 tank is a huge pain!!

 

[143MPCo]

I completely understand the discussion's roots. What complicates things is your choice of pumps for the comparison. You just don't choose a pressure rated pump for a closed loop when you remotely care about energy efficiency. Coming from Southern California, I have a lot of experience with energy efficiency as anyone with a 200+g reef tank here is likely paying upwards of $.32 - .43 per kWh. I went from closed loop to Tunze propellor pumps 12 years ago when we did not nearly have the energy efficient pump choices that we have today.

That’s the point I was trying to convey, otherwise I would have chosen more energy efficient pumps. When most aquarist looking to setup a CL system for the first time, I really doubt that energy efficiency is at the top of their list. They’re more concerned with flow and less with how it will impact the bottom line.

Side note: "$.32 - .43 per kWh" ouch!

Where the comparison gets sticky is here. we are comparing this pump to a single Ecodrift 20.0 that puts out 5000 gph at 60w. You can't compare the 4200 gph of a dart to the 5000 gph to the Ecodrift. Imagine a 1 1/2" return directly in a 200g aquarium. Flow would be insanely chaotic. But that's not the case with the Ecodrift even though it has more GPH. This is due to the velocity of the water movement. Since running a 1 1/2" inlet straight from the Dart is not realistic we split the flow into two smaller 1 1/4" pipes. This is still a ton of flow. So to get a better comparison, you get a second Ecodrift 20.0 and now you are at 120w.

Assuming for a second that splitting the flow is at exactly the same length of PVC without negating the fact that restrictions will occur due to contributing factors such as 90 degree bends, less so with 45’s. You would in actuality be cutting the flow in half, by that same premise adding an addition powerhead running at half the speed would cut wattage in half and drop from 60 watts to 30 watts, but 60 watts total for the additional power head.

At this point you are probably saying, "but the controllable Ecodrifts can run at different speeds and that will on average cut power usage to 40w per pump. You could then swap the Dart for a Vectra L1 and you also have the ability to pulse and decrease the average wattage. In the end, the Ecodrifts/or other propellor pumps are still the better choice for energy efficiency

I agree, I don’t think I stated otherwise anywhere in this thread.

 

[Paul Carpenter]

I just did the calculations for a build I'm putting together. 36000 gph total flow.

If I ran closed loop it would look like this....WITHOUT buying the plumbing bits...

Pricing per month:
Return pump: tiger shark $93
Skimmer pump: dart $14
Closed loop pumps: manta ray x4 $270
2x gyre 150s: $9

Total cost per month: $386 or $4632 per year!!!!!

Cost with DC pumps

Per month:

Return: 2x vectra l1s: $22
Skimmer: 1x vectra L1 $11
Flow: ecodrift 20s x4 $21
2x gyre 150s: $9

Total cost is $63 per month or $756 per year.

Savings of $3876 per year for a huge amount of water flow.

It would cost me 6x as much per year to run a closed loop system on my 600 gallon tank. I can't ignore that.

 

[Paul Carpenter]

Case closed. HELLO DC PUMPS, goodbye loop!