Tank electricity costs – especially heaters monsterfishkeepers.com electricity merit badge pamphlet


I have 5 tanks so I needed a better idea. Over two weeks I randomly walked by the tanks and checked off on a piece of paper if the heater was on or off. I tried to do it randomly, not every 10 minutes in case a heater was running say, an 8 min. off, 2 min. on cycle. I did this about a 100 times over many days but it took less time than sitting watching a tank for two hours. The 45 gallon tank was on 20.3% of the time so I feel my method was fairly accurate. The chart below shows my results at 6 cents per kilowatt hour.

What amazed me was how efficient large tanks are at conserving heat. The watts/gallon figures are not used in calculating dollar costs but make for interesting comparisons. gas natural inc You would think that the more watts per gallon you have, the less the heater would be on. Surprisingly, that is not always the case. I was worried about heating a 180 gallon tank with a 250 W heater (would it be enough heat output?) but it is on less often than the same size and brand heater on my 90 gallon. I surmise that this is due to the larger volume of water retaining heat better and the fact that the glass is thicker. Also my 180 gallon is my only tank with foam insulation underneath so maybe that makes a difference. Other factors that could affect your heating are: the location of the tank (by a window, wall, open door), the type water movement in the tank, location of heat vents in the home, and the type and amount of covering for the tank. [so tell the spouse you need a bigger tank and it won’t cost any more to run it!!! (At least the electricity part)].

In case you wonder how to calculate the cost of the heater, I will give you an example. My 200 W heater is on 20.3% of the time so that is 20.3% out of 24 hours so .203 x 24 x 30.4 days in a month = 148.1 hours a month. 148.1 x 200 Watts = 29,620. I am paying 6 cents per kilowatt hour so that is 29,620/1000 x .06 = $1.78 per month. gas definition chemistry You can calculate your lights and filters the same way.

I calculated that the cost total for electricity for the 5 tanks I have, to be $19.72 per month, which averages out to $3.94 a month per tank. 70% of that electrical cost is for heaters, 22% for filters, and 8% for lights. I do not have LED lighting. gas x user reviews If you live in an area where your home is above 70 degrees F much of the time because of the warm weather, your heating costs would be less. If you are heavily into lighting, that portion will be more.

So there you have it. If you are too lazy to do all this math and recordkeeping, you can use the $3.94 a month per tank average for light, filter, and heater expenses if your electricity rate is around 6 cents per kilowatt hour. A 9 cent/kwh rate would be $5.92 a month per tank; 12 cents/kwh is $7.88 a month per tank and 18 cents works out to $11.82 a month per tank.

I also keep my current tanks inside my residence so have a similar difference between the ambient room temp and tank temp is similar. Around ten degrees for me. I add that some keep tanks in basements or a garage or other structure not necessarily kept at home room temps. Perhaps the structure is not heated at all. I knew a fellow who used part of his green house business to run fish shop from. I have also kept tanks in a basement with a slab floor so I could keep bigger tanks. More tank heating cost in these sorts of structures.

Big tanks may be good at retaining heat for the similar reason some elephants have large ears. gas efficient suv 2008 I think of it as the inverse square rule. If I recall correctly it goes that if the surface area of a shape is doubled then the internal volume increases by four times. Something like comparing the internal volume of a volleyball to than of a basketball. You should be able to add multiples of water volume to the basketball even tho it is only roughly twice the diameter.

A tank with twice the surface area of the glass panels should hold around four times the volume ( think mass) of water. Same for an elephant that has a large outside surface area and is also crammed full of an even larger mass of wet meat. The bigger tank with a multiple increase of water mass will hold the heat. Back to some elephants, the large ears are laced with blood vessels to act as radiators so they can lose some heat.

Water also has a physical property which makes it hold heat ( I forget the physical term just now). It can take a while to warm up but once warm will lose that heat slowly. For example I now have a wood burner in my home made of iron or steel. When I get a good fire going that steel gets hot. I also sit a four gallon stainless stock pot of water on the stove which gets hot. j gastroenterology impact factor When I let the fire burn out the stove will get cool to the touch much sooner ( by many hours) than the pot of water.