Aquarium equipment power usage observations

[linuxrulesusa]

Well, power usage calculators are a grand thing, e.g. measuring power draw written on the box, like 200W for a heater, then using formulas like the below to calculate approximate usage.

power draw x hours per day x days per year = KWH used     

Multiply KWh used x KW cost = yearly cost       

Divide yearly cost by 12 = monthly cost

To see if my estimates were accurate, I decided to pick up a watt meter, specifically the P3 P4400 Kill A Watt meter.  I know it's not 100% accurate, especially compared to professional tools used by electricians, but it should get close enough for my purpose.

I tested it last night on the power strip used by two of my tanks, and got a bit of a shock (mentally, not literally).  I spot checked several times in an hour and saw the minimum power usage  with heaters off was around 42W.  Then I waited until both heaters kicked on - and the power usage bumped up to 332 W.  This makes sense with a 200W heater + 100W heater + other equipment.

That was an on the spot test, so I let the meter run to measure for 12 hours.  I figured the actual usage would be something around half, e.g. 0.15KW/hour.  Nope, it was actually 0.2KW/hour, so 78% of the maximum.  Working backward, e.g. tweaking my numbers in the formula until I got about the same measurement indicates my heaters are running more like 18hrs/day during the winter, at least on a cold day like yesterday with outside temp around 20 degrees Fahrenheit. This was a huge jump vs. the 6hrs/day I had used as my estimate for the power calculation spreadsheeet.  Obviously those numbers should be much lower in the summer, but it was eye opening to see how far off I was.

Looks like I need to bump those heaters down a few degrees periodically to get the hardier fish acclimated to around 72 vs. 78-80.

I also have three more banks/power strips of tanks I need to measure.  I plan to run the meter for 24 hours on each to get rough numbers to work from.  I realize it will be more accurate if I do this test a few times a year when the temperature is warmer or colder.  I plan to do this as I have time.

Anyway, I found this informative, and it might be helpful if you're seeing spikes in your electrical costs.  Check your heaters and other equipment to see how often they're actually running.

[four_by_ken]

Now, dont get me wrong... I find this type of stuff VERY interesting.  In fact, I would like to test out all my stuff to see where I stand also.


That being said... my findings wont change anything.  It will just show me the numbers... and I will suck it up and live with it.  I dont want to sacrifice my fish to save a couple bucks by lowering the heaters.

[linuxrulesusa]

Now, dont get me wrong... I find this type of stuff VERY interesting.  In fact, I would like to test out all my stuff to see where I stand also.


That being said... my findings wont change anything.  It will just show me the numbers... and I will suck it up and live with it.  I don't want to sacrifice my fish to save a couple bucks by lowering the heaters.

I'm sure it depends on which fish you have. 

In your case, some of the African cichlids may be more sensitive to colder temperatures, but for my Central American cichlids and some of the oddballs, I don't think they'll be as temperature sensitive.  Obviously if they showed signs of distress or sickness I would make a call about raising the temps again, but if you can drop the heaters even 3-4 degrees I think there could be a pretty significant difference in cost. 

I'll have more data in a few weeks hopefully.

[Maize-N-Blue-D]

My first worry would be ich...Dropping the temps in the tank would increase the likelyhood of ich developing.  That alone stops me from dropping the temps in my tanks...

[linuxrulesusa]

My first worry would be ich...Dropping the temps in the tank would increase the likelyhood of ich developing.  That alone stops me from dropping the temps in my tanks...

Dropping them drastically yes.  Dropping them over a period of weeks...I don't think necessarily.

[four_by_ken]

I am really curious as to what the difference will make.  I really dont think it will be THAT drastic.

Did you test it when the temps were in the -10 degree days?  Might want to test this weekend or so when the temps are more common.

[linuxrulesusa]

I am really curious as to what the difference will make.  I really dont think it will be THAT drastic.

Did you test it when the temps were in the -10 degree days?  Might want to test this weekend or so when the temps are more common.

I tested last night.

[linuxrulesusa]

Assuming I recorded everything correctly, here's what I found on the first set of tanks.

At 12 hours, the usage was 0.2 kw/h (~2.42kw total).

At 21 hours, the usage was down to 0.13 kw/h (~2.76 kw total). 

I think your point about temperature was a good one Ken.  I will test again next week when temps outside are in the 40s or so.  My furnace/thermostat doesn't help because it tends not to kick on very quickly so the temp often drops to say 64-65 even if the temp is set at 68 before it turns on again. 

I'm testing another set of tanks at the moment (3 20 highs with two 200w heaters, so that will give me another comparison point).  Will go back and retest the 12 cube (100W) and 50 long (200W) later to compare.

[mightieskeeper]

Great topic.  I have 2 wet drys running, pump electric usage is important to know.  I don't want to use a pump that is going to cost twice as much to operate day to day.

[linuxrulesusa]

So far the experiment is going well.  I'll post some data next week hopefully.

[danielratti]

My wetdry that's a 55 that's normally half full with 2 300 watt heaters and a mag 18 costs 24 dollars a month to run. Yay science.