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emm0909
07/20/2009, 08:06 AM
I am trying to calculate the amount of electricity that my aquarium is drawing but have a few questions about electricity. Figured DIY guys were the best to ask.

If my light runs four 54 watt bulbs - 216 watts, does that mean that it'll draw 216 watts/hour?
If that is correct, eight hours would be 1.728 kw per day. (Multiply that by what my bill states and that's it?)

Or do I really need to get into the amps/ohms that each piece of equipment draws?

der_wille_zur_macht
07/20/2009, 08:11 AM
<a href=showthread.php?s=&postid=15382517#post15382517 target=_blank>Originally posted</a> by emm0909

If my light runs four 54 watt bulbs - 216 watts, does that mean that it'll draw 216 watts/hour?


It'll draw something more than 216 watts, depending on efficiency of the ballasts, etc. A good rule of thumb might be to assume 10 - 20% loss, so your 216w fixture might be drawing more like 250 watts.

And, the sentence "this fixture draws 250w" has no time component - so, if you leave it on for one hour, then yeah, you'll use 250 watt-hours of power. Or, 1.whatever kwh a day, for a given photoperiod.

The easiest way to answer all of these questions is to get a kill-a-watt meter, and plug your various equipment in to it:

http://www.amazon.com/P3-International-P4400-Electricity-Monitor/dp/B00009MDBU/ref=sr_1_1?ie=UTF8&s=electronics&qid=1248099035&sr=8-1

These devices are basically designed to answer exactly the sorts of questions you are asking.

emm0909
07/20/2009, 08:32 AM
Thanks, maybe I'll pick one of those up. But to move on without one here's another example.

If I know the about of amps it pulls I could figure out the kWh. I have a fan in my room that is 2.2 amp. It plugs into a normal 120 outlet.

2.2*120 = 264 watts
264/1000 = .264 kW
.264* hours use (say 3) = .792
.792* cost per kW on bill = What you're paying to run that fan for three hours.

Correct? Anyone? I think i'm going to buy one of those meters.

der_wille_zur_macht
07/20/2009, 08:39 AM
Your math will get you in the right realm, but there is a huge room for error. Just buy the kill-a-watt. :)

I'm sure that one of the EEs in here will be along shortly to explain the gory details, if you're interested!

troylee
07/20/2009, 09:46 AM
rc has a calculator that does all the math for ya somewhere....cant seem to find it lately, but anyways another route is pick up a killowatt meter from new egg... they run like $15 and plug your tank into it and it will tell you watts, amps, killowatts, etc.....also one of the best tools you can own for tuning skimmers....;)

insane
07/20/2009, 09:58 AM
Check the specifications on your ballast. It should tell you the wattage it needs, not the wattage it can suppport. It will also tell you the amps it draws. Older balast more than likely will not have a sticker stating its' draws

It is like when someone looks on the back of their home stereo and it says 500watts near the power cord. That doesn't mean you are pumping out 500 watts to your speakers. It is how many watts of electricity your stereo is drawing through the power cord

emm0909
07/20/2009, 10:10 AM
OK, I guess that answers my question. Now to steal my own thread:

How does a kW meter help tune in your skimmer?

troylee
07/20/2009, 10:44 AM
When you do mods like meshing for example you get a before and after reading to see if its drawing less watts, if its to much trim a little till you get the number you want.........when pretty much doing anything like changing the depth of the water its in buy a inch can change the wattage buy a consederable amount like 20 or 30 watts...its all about the game of effincency...;) and pump life...its a whole other thread in its self.......
A killowatt meter and a dywer schf gauge are essentials in tuning a skimmer......;)

emm0909
07/20/2009, 11:42 AM
Once again, taking this thread in another direction. I know that if you're trying to watch your power consumption you should think about getting out of the hobby all together but hear me out. I have a 75rr with a 20 gallon sump. I am converting the system over to SPS & LPS w/ about seven fish.

I was thinking of placing the sump on a timer. If around 2 in the morning I kick it off. (Skimmer, carbon, heater and return pump) Then around 8am I could kick it back on. That time off will not be enough to damage much. I'm wet skimming anyway so if the skimmer is off for six hours a day I don't think it'll much matter. The heater wont make a difference here in the summer and I think I run enough carbon out of a Fluval 404 that it'll do it's job in the day. Do you think the tank would suffer from this? How?

troylee
07/20/2009, 11:51 AM
i have heard of people reducing flow at night by turning power heads off to similate the oceans calming at night....but never taking a sump off line....i will let someone else answer that.....i wouldnt recomend it thou.....

saveafish
07/20/2009, 11:58 AM
NOOO!! never shut the system down. even 20 minutes will cause a off balance somewhere. It is like this. lets say you are on life sopport and the DR. says hey we need to cut cost so we are going to un plug your bodie for 2 minutes ever hr. in thim your bodie will crash and die.

emm0909
07/20/2009, 12:05 PM
Alright, I'm going to get the meter and check it out. Then I'm going to go around the house and check every thing that uses electricity and find out how much energy my roomate wastes. He got the bill yesterday and called me right up saying "Dude, we need to watch power. I'm talking lights, everything. We can't leave things on when we're not there." Hen he blamed my fish tank of all of it. Understandable. He left the house shortly after that. Eight hours later I come home to two box fans in the windows turned on as high as they will go. Moron.

der_wille_zur_macht
07/20/2009, 12:07 PM
Shutting down your sump is a bad idea for several reasons. Firstly, the vast majority of gas exchange in a modern reef aquarium (indirectly) coming from the sump - the skimmer provides a ton of aeration, and the skimming action of the overflow box promotes gas exchange in the display tank. Turning the sump off is like cutting the oxygen content in your system. This would be an especially bad idea at night, since that's when everything (animals AND plants) is respiring, i.e. using up oxygen - as opposed to during the day, when the photosynthetic life in your tank is actually producing oxygen.

Plus, many skimmers take some time to get up to production, so shutting it off every day could cause a pretty significant loss of performance.

If you want to save power, look at some more obvious places to cut back. I would bet that the biggest consumption of power on most reef tanks is lighting. Changing from MH to LED could net you a 50% power savings on lighting (plus, no bulb change costs, since LEDs last for years.) Even if you don't want to switch lighting technologies, being careful about component changes can make a huge difference. Lamp and reflector selection can alter output of a MH fixture by 50% or more, for the same power consumption. For instance, you might find that you can go from 400w to 250w MH and get the same output, if you pay careful attention to bulb choice and switch from cheapo spider reflectors to lumen brights.

Another area to examine is water flow. A closed loop capable of doing 2,000 - 3,000 gph might draw 200 - 300 watts, while a pair of Tunze streams producing the same amount of flow might draw 50 watts.

emm0909
07/20/2009, 12:16 PM
One place I can cut back instantly is my return pump. I'm running a throttled back Mag 9.5. That could easily be replaced with a Mag 7 or probably even a Mag 5. I have a K2 & and K3, soon to be a K3 & K4 for flow but that's it. My lighting is a 4 bulb Tek light t5. Awesome light. 216 watts in light + good ballasts.

I was thinking of rigging something up for my carbon to cut one pump out as well. If I could somehow use my overflow water to run through the carbon and then into the sump I would be able to cut out the Fluval.

I'm not about to put anything smaller on my skimmer (G1X). That's not worth sacrificing.

Thank God for this cool summer so far. I haven't had to hook up the chiller yet.

der_wille_zur_macht
07/20/2009, 12:21 PM
Rather than trying to run your overflow water through equipment, you'd probably be better off running your return water through it. Messing with your drain can be really dangerous - if things got clogged to the point of reducing flow, your return pump would empty the sump into the display, which would then overflow.

insane
07/20/2009, 12:56 PM
<a href=showthread.php?s=&postid=15383900#post15383900 target=_blank>Originally posted</a> by emm0909
One place I can cut back instantly is my return pump. I'm running a throttled back Mag 9.5. That could easily be replaced with a Mag 7 or probably even a Mag 5. I have a K2 & and K3, soon to be a K3 & K4 for flow but that's it. My lighting is a 4 bulb Tek light t5. Awesome light. 216 watts in light + good ballasts.

I was thinking of rigging something up for my carbon to cut one pump out as well. If I could somehow use my overflow water to run through the carbon and then into the sump I would be able to cut out the Fluval.

I'm not about to put anything smaller on my skimmer (G1X). That's not worth sacrificing.

Thank God for this cool summer so far. I haven't had to hook up the chiller yet.

I too am working on the less pumps, less heat, less electricity, less wires thing as well.

I am also pondering the carbon only inline on the return with a Nuclear chemical filter. As I have been told if I do this, include a bypass around it for when not in use or for changing media, etc. So your system can stay running while working on it.

Filter bodies are approximately 13" wide and 12.5" tall (overall width with fittings is 15”).

1" FNPT inlet and outlet ports allowing for higher flow rates (up to 1,200 gallons/hr) than similar filters with 3/4” ports.

All models come with adapters for 3/4" and 1" hose, stainless steel hose clamps, Teflon tape, and a drain valve.

They hold 7lbs of media but you could do half bio balls, live rock rubble or whatever in it. Just what I have been considering along those lines.

The cheapest method would be fill a media bag with carbon and place it in your sump across the flow if you have room for it.

emm0909
07/20/2009, 01:21 PM
I don't think that a media bag full of carbon sitting in the sump is sufficient. I think that you need to have water forced through it.

BeanAnimal
07/20/2009, 02:38 PM
<a href=showthread.php?s=&postid=15383101#post15383101 target=_blank>Originally posted</a> by insane
Check the specifications on your ballast. It should tell you the wattage it needs, not the wattage it can suppport. It will also tell you the amps it draws. Older balast more than likely will not have a sticker stating its' draws

It is like when someone looks on the back of their home stereo and it says 500watts near the power cord. That doesn't mean you are pumping out 500 watts to your speakers. It is how many watts of electricity your stereo is drawing through the power cord

Likewise, if the nameplate by the power cord says 300W, there is no way that your 2 channel amps is 200W per channel, no matter what the sales literature says :)

BeanAnimal
07/20/2009, 03:06 PM
<a href=showthread.php?s=&postid=15383900#post15383900 target=_blank>Originally posted</a> by emm0909
One place I can cut back instantly is my return pump. I'm running a throttled back Mag 9.5. That could easily be replaced with a Mag 7 or probably even a Mag 5.

mag 9.5 is 93W
Mag 7 is 60W
mag 5 is 45W

The saving by dropping to a Mag 7 would be 33W per hour or .792 kWh per day. That is 290 kWh per year or about $43 a year in savings. (less than $1.50 per month).

The savings by dropping to a mag 5 would be 48W per hour or 1.152 kWh per day. That is 420 kWh per year or about $63 a year in savings (about $2 per month).

I used $0.15 per kWh, your rates may differ :)

MattShack
07/21/2009, 07:31 PM
Watts Used / 1000 x Your kWh Rate = $ per hour for that item
$ per hour x hours on per day x 30 days = $ per month for that item

Using Beans Mag 9.5 @ 93 watts and $0.15 per kWh (mine is $0.08 kWh,so as Bean suggested, check yours):

93 watts / 1000 x $0.15 kWh = $0.01395 per hour
$0.01395 x 24hrs = $0.3348 per day
$0.3348 x 30 days = $10.04 per month

For 1 54 watt T5 (which is about 57 watts used)
57 watts / 1000 x $0.15 = $0.00855
$0.00855 x say 10 hours per day = $0.0855
$0.0855 x 30 days = $2.57 per month for 1 T5

Do this for each piece of equipment to get your total cost per month.