...are closed loops becoming obsolete?

143MPCo · Oct 14, 2015

...at MACNA 2015 I recall Sanjay Joshi talking about how closed loops have become obsolete with the introduction of DC powerhead at a cheaper price point... he made a compelling argument related to cost of an additional pump/s or more, PVC plumbing needs, and the fact that DC powerheads have becoming considerably more reliable... he also noted the the kilowatt an hour cost to run the big closed loop pump on a system was an additional factor in his research and why he's moving away or considering moving away from closed loops.

...personally, whether or not this move away from closed loops becomes mainstream or not is questionable, I'm all for saving money anyway I can as my electric bill is high enough and why I opted not to go closed loop... one just has to look at wattages used on a AC vs DC pump to see that you're at a much higher kilowatt an hour cost for just one pump.

A quick side by side and break out (I just picked a DC powerhead I saw at MACNA, sure others might be better)...

Aqua Medic EcoDrift 20.0 with Controller
Power Consumption: 20 – 60 watts

Specifications (Hammerhead Gold):
Maximum Wattage: 297W
Average Wattage: 272W

Specifications (Barracuda Gold):
Maximum Wattage: 253W
Average Wattage: 237W

...this roughly equates to 4 Aqua Medic EcoDrift powerheads each with an adjustable capacity flowrate of 2641 – 5283 gph (inside your systems with no head pressure concerns), one Hammerhead Gold Maximum Flow Rate: 5555gph, Barracuda Gold Maximum Flow Rate: 4680gph. you also need to consider, that's a flowrate at 0 head pressure and when all the plumbing is said and done on a closed loop, flow is and will be less.

Your Hammerhead Gold runs 24 hours a day, and consume 297 watts of electricity.

297 watts X 24 hours = 7,128 watt-hours per day
7,128 watt-hours per day / 1000 = 7.12 kWh per day
7.12 kWh per day X 30 days = 213.84 kWh per month
213.84 kWh per month x $0.12 per kWh = $25.66 per month (one pump)
$25.66 x 1yr = $307.92 not including line fees and tax.

Same breakdown of the above DC pump will cost you $62.20 a yr (one pump) to run, again not including line fees and tax.

So I'm curious to know what you all think, aesthetics aside, are closed loops becoming obsolete?

Daniel@R2R · Oct 14, 2015

Following! I'm building a peninsula, so a closed loop is in consideration just to keep powerheads off the other 3 panels (I don't really care if they're on the back wall).

dkray944 · Oct 14, 2015

I personally went against a closed loop system for all of the reasons you listed above on my 320g build. I think another thing to consider is that the more holes you have on your tank the more opportunity you have for a leak.

Daniel@R2R · Oct 14, 2015

dkray944 said:
I personally went against a closed loop system for all of the reasons you listed above on my 320g build. I think another thing to consider is that the more holes you have on your tank the more opportunity you have for a leak.

This is my biggest fear and main reason I'm vacillating on the idea.

Helenareefer · Oct 14, 2015

You don’t necessarily have to have any holes in the tank for a closed loop. Also, with some new powerful DC return pumps the energy consumption could even be less than multiple power heads.

drstratton · Oct 14, 2015

Do you have an example of a build utilizing this method? I'm hoping to build a new tank and I'm exploring all of my options. The savings in the cost of power used is a huge plus.
Thanks!

twilliard · Oct 14, 2015

All good valid points.
I had a closed loop in the past and when you have a large 120v pump running 24 hours a day the cost goes out the roof.
My goal is to be all DC by the end of the year

143MPCo · Oct 14, 2015

Helenareefer said:
You don’t necessarily have to have any holes in the tank for a closed loop.

Hello @Helenareefer can you give an example of what you mean by this, most if not all the "closed loops" I have seen take water directly from the DT (normally from the bottom of the tank) and return it without draining via an overflow.

143MPCo · Oct 14, 2015

drstratton said:
Do you have an example of a build utilizing this method? I'm hoping to build a new tank and I'm exploring all of my options. The savings in the cost of power used is a huge plus.
Thanks!

typical closed loop...

Powerheads...

Helenareefer · Oct 14, 2015

143MPCo said:
Hello @Helenareefer can you give an example of what you mean by this, most if not all the "closed loops" I have seen take water directly from the DT (normally from the bottom of the tank) and return it without draining via an overflow.

Just pointing out that you could pull water from the tank with no holes, and return over the side. Not as ascetically pleasing mind you, but it is an option. And, say you plan on having a canopy, it’s not even noticeable.

drstratton · Oct 14, 2015

Thank you for the example!

Helenareefer · Oct 14, 2015

143MPCo said:
Hello @Helenareefer can you give an example of what you mean by this, most if not all the "closed loops" I have seen take water directly from the DT (normally from the bottom of the tank) and return it without draining via an overflow.

Just an example picture...I will look for more.

143MPCo · Oct 14, 2015

drstratton said:
Thank you for the example!

you're welcome!

Helenareefer · Oct 14, 2015

Primitive drawing example...

dbl · Oct 14, 2015

FWIW, and I didn’t know anything about any of this stuff (and probably still don’t), but I did a CL on my peninsula a year and half ago. I too didn’t want to see any powerheads on the three viewable sides. I have two holes drilled in the “wall” side and I return them over the top. I chose to return over the top because I knew I would have a canopy to hide all the ugliness.

I ran that way for the first year without issue. However, a few months ago, I actually added a Gyre 150 to the wall side, actually mounted inside my overflow box. Discovered SPS want a little more flow than I was getting prior to its addition.

I’m sure the power consumption is far greater using the CL pumps, but in my case, my electric bill only went up by about $30/month for my entire system, so honestly, it simply didn’t bother me.

143MPCo · Oct 14, 2015

Helenareefer said:
Primitive drawing example...

ahh, thank you for posting that... would you happen to know what marine grade self-priming pump they used?

Helenareefer · Oct 14, 2015

143MPCo said:
ahh, thank you posting that... would you happen to know what marine grade self-priming pump they used?

Not a clue, just googled some images.

143MPCo · Oct 14, 2015

dbl said:
FWIW, and I didn’t know anything about any of this stuff (and probably still don’t), but I did a CL on my peninsula a year and half ago. I too didn’t want to see any powerheads on the three viewable sides. I have two holes drilled in the “wall” side and I return them over the top. I chose to return over the top because I knew I would have a canopy to hide all the ugliness.

I ran that way for the first year without issue. However, a few months ago, I actually added a Gyre 150 to the wall side, actually mounted inside my overflow box. Discovered SPS want a little more flow than I was getting prior to its addition.

I’m sure the power consumption is far greater using the CL pumps, but in my case, my electric bill only went up by about $30/month for my entire system, so honestly, it simply didn’t bother me.

thank you for sharing this!
$30 a month more?

Shep · Oct 14, 2015

....this might be a really dumb question but what exactly is a closed loop system and what makes it different than a normal tank w/sump?

twilliard · Oct 14, 2015

143MPCo said:
ahh, thank you posting that... would you happen to know what marine grade self-priming pump they used?

That right there was a huge issue for my closed loop system.
Priming the pump.
I was using a reeflo pump and had to build a stand pipe to prime it after cleaning.