Heating question

[AquaticTim]

As I ponder my dream tank, I've always wondered one thing. How the heck do they heat larger aquariums? IF you figure the 2-5 watts per gallon on a 1000 gallon tank, that's 2k to 5k watts.. IS simply putting 6 of the 1,000watt submersibles in the sump the only option aside from running a dedicated hot water heater? I did some research, and always came up short when it came to this area. (This would be a saltwater set-up, 540 gallon tank, (8ft x 3 ft x 3ft), with a 100 gallon sumpfugium, and an additonal 100 gallon tank in line simply for additional water in the system, and to grow any "feeder" fish, amphipods, and/or copepods... probably close to 50 gallons in the skimmer and lines.. (this comes to 800 gallons, but I like to figure 1000 to be safe). SO I guess my question is- WHat is the simplest/most cost effective way to heat a 1000 gallon system?

 

[fishwish34]

That's a good question! I wonder how the public aquariums do it...I mean, you don't see a giant-sized Petco heater in there, do you?

 

[skjl47]

Hello; As long as you are dreaming, allow me to chime in. Once the water has been brought up to temperature, you will only have to replace the heat lost. Water will hold heat for a long time. (Think of how long in the fall you can still swim in a lake after the air temps are quite cool.) Water is slow to heat up and slow to cool down.

Another consideration is the mass of the water compared to the surface area of the tank. In biology the example is a mouse versus an elephant. A mouse (Hummingbird, shrew) has a mass to surface area of skin ratio that is close to 1:1. The mouse will lose a large amount of heat thru the skin and has to consume a lot of calories to keep alive. (A shrew must eat several times it’s body weight each day to stay alive. Hummingbirds go into a state of torpor an night to conserve energy.) An elephant has a body mass that is magnitudes larger than the surface area of the skin. A large elephant can get by on a few hundred pounds of low energy plant material each day. (They have the large vein rich ears to get rid of heat.) (Many cold adapted animals have large bodies.) It is the inverse square rule. Think of a six inch diameter ball, say soccer sized, compared to a twelve inch diameter ball, say basket ball sized. The 12 inch will have four times the internal volume as the six inch ball. Each doubling of surface area yields around four times increase in volume. The larger the tank the slower should be the heat loss. A possible advantage in the winter might be that the huge mass of water will lower the heating bill for the entire house. (Speaking of heat, it is 15 degrees F outside here at this moment.)
I also would insulate the non viewing sides of the tank and the cover to help slow heat loss. I would also design a tight cover to reduce evaporation. Think of how much moisture would escape into the house during the winter.

 

[Lotus]

The other thing you might consider on a tank that size is an integrated heating/chilling system. Because they're on a controller, you're less likely to have the tank overheat.

This is one type (yes, they're expensive): Store Chillers In-Line Chillers

If you're going reef, you may well need a chiller if you have lots of lights and pumps going.

 

[skjl47]

Hello; Another thought. A friend has a heated spa. It may well be around 1000 gallons. It has a heater as well as circulating pumps. he claims that it not expensive to heat. It also has a floating foam cover to hold in the heat. Perhaps the guts of one of these can be adapted for an aquarium.

 

[AquaticTim]

Thanks for the ideas!

Here in Wisconsin, we heat our house in the winter, and have A/C running in the summer, so the temp range of the house is always between 68 to 74degrees. My tank would likely be in the basement, so I doubt it would ever be above 72 at the most for room temp. This said, I don't know that I would need a chiller (unless other equipment running would give off enough heat to need one). I have seen these before, and they are pricey.. just wondering if there are other options.


I actually did some part time work for a hot tub repair man, and am sure I could pick up a heater at a reasonable cost... Then would need to rig up a thermostat for it.. I am SURE it would not be as effiecent as in hot tub set up, as in a hot tub there are generally packed full of insulation or foam around the sides, and have a 4-8 inch insulated cover when not in use. I would imagine half inch of acrylic without a truly sealed top would lose much more heat. But still be a cheaper option at least up front. My only concern is whether or not it would be safe with saltwater.. Has anyone else tried this option or know of a saltwater forum that specializes in larger aquariums?

 

[AquaticTim]

I've done a little more research elsewhere, and some people claim on a tank this large, with heavy lighting (which I would have) that they don't need a heater... Claiming it stays between 76-82 degrees on 500 gallon systems... Any one on this site with a 500 gallon or larger tank.. and if so, any comments?

 

[Newman]

that all depends on your ambient room temp. all year round if you have no heater you better be heating your tank room to the right temp.