I had a curious thought today...

Is it possible to get heated shelves that heat the tanks that sit on it?

kind of like the heated towel racks but set to heat the water to a certain temp.

You can get heat pads to put under tanks with a thermostat in the tank.. Some people have even made their own.

I've seen racks set up with either those under gravel heating wires or a form of heating wire for reptiles

I have a double tank stand with two 1200mm long tanks and each tank is heated with an undertank heating element controlled by a thermostat. The top tank is divided into 6 seperate tanks and normally used for breeding and the bottom tank for growing plants. Pretty quiet at the moment as somebody keeps shaking them.

Our 4ft sits on a heat pad Grant made for it. I think they are a good idea as heat rises and you have less equipment to hide (and large fish to break) in the tank itself.

Our 4ft sits on a heat pad Grant made for it. I think they are a good idea as heat rises and you have less equipment to hide (and large fish to break) in the tank itself.

How would one construct a heat pad?

By purchasing some heating cable and burying it in a bed of sand as-per the instructions.

Try Pacific Growers in Mt Wellington.

I would think this is a very inefficient way of heating a fishtank.. especially compared to a in tank/in sump heater where all the energy goes directly into the water.

A heat pad would have to be insulated under it unless you are also wanting to heat up the room.

And what is the heat gradient like through your substrate Alanmin? Doesn't the substrate get very hot at the bottom and what about the plants roots?

Personally I think it's a terrible idea trying to heat a fishtank from the outside through the substrate.

It actually works very well and I would think is pretty efficient. The heat pad is a professionally made one and the thermostat is very accurate. The polystyrene is underneath the mat and that covers the complete footprint of the tank. You need to have a relatively shallow media layer (mine is sand and about 30mm deep. If you have it too thick or uneven there will be problems. There is a lag period from when the thermostat turns the heat off which gives a bit of variation in temperature but not enough to cause a problem to plants or fish. It has CO2 injection and the plants do well in there.

Are they cheap to buy/run?

I may put one under a row of tanks that I need to set up but don't want to put heaters in

Sound like a good idea, sounds like it'll be pretty good for plants too. Like the heating cables sold in the LFS, but no cables in the tank for roots to get tangled in. I can't imagine how it's implemented though? I imagine it goes something like this from top to bottom: Base of tank -> sand + cable -> polestyrene -> stand. But considering that I've heard of heaters melting poly backgrounds a little, I would think you'd need a decent layer of sand (more than 30mm) to insulted the poly from the heat. Also wondering how you get the sand to stay in place without getting squished out between the tank and poly and how can you make sure the sand is flat and even enough to not cause any issues with the tank's weight distribution? I have a feeling that the answer to some of these questions will make me want to whack my head on the table and wonder why I didn't think of it in the first place, but I'm tired, so I'm just going to ask this anyways .

I had mine made by Argus Heating a few years ago and it cost a bit over $100. Thermostat was from Homershams for about the same. You give Argus the footprint and wattage you want and they will sort it out.

We made our own. An article on how to do so was in an Aquarium World years ago and if anyone wants a copy I am happy to email it. Be aware, if you do not have basic electrical certification I suggest you get an electrician or someone who knows what they are doing. If you get it wrong and it overheats, shorts out or something and burns down your house, insurance will not pay out.

Our heat pad is not buried in the substrate, it sits under the tank itself. It is wire (like that used in electric blankets) coiled on Pinex. The wire just sits on the Pinex and was taped down with parcel tape. Because it is evenly spread it does not cause stress on the tank base.

Like Alan, we got Argus Heating to do the plugs and have them heat shrinked and sealed. Our heat pad has been running for over 10 years now. The only problem we had was when the thermostat died and we had to replace it. That is the hardest part now - finding a suitable thermostat. They only produce all in one heaterstats now.

That is the hardest part now - finding a suitable thermostat. They only produce all in one heaterstats now.

There are quite a few temperature controllers available for marine tanks. They're a bit expensive and probably wouldn't really work very well for dozens of tanks off a single giant heatpad.