Heating tanks above 90*F?

[SkyStevens]

Hello, I am new to the site and have a question about aquarium heaters.

I am a PhD student at the University of Connecticut studying Ranavirus in wood frogs. I will have outdoor mesocosms made from 50G stock tanks. One of my treatments is temperature and I will have heated tanks paired with ambient temperature tanks. I will have Arduino chips that monitor temperatures and turn on tank heaters with the idea of keeping the heated tanks 3*C higher than the paired ambient tanks. My problem is that we expect the temperatures to get fairly high in the non-heated tanks, as they are small and will only have 50% shade from the lids. If the ambient tanks get over 90*F then the heaters with thermostats might not be able to heat the ambient tanks to 95* (a 3*C difference). Does anyone know of a 300W tank heater without a thermostat or one in which the thermostat could easily be disabled? I will have the Arduinos monitoring the temperature and cutting power to the heaters once the temperature is right, so I don't think I have to worry about a heater going out of control. But I also have no idea about this because I am a total noob when it comes to fish tanks. Anyway, thanks in advance for any and all help!

 

[FreshyFresh]

From what I've used, ~25watts for each ~10gal of water will heat the tank and maintain it to at least 10deg above ambient.

If you need a tighter span of heating above ambient, I'd use a temperature controller that you plug the heater into.

 

[Rbishop]

Is the room where the tanks are on some set (and maintained) temp range?

 

[SkyStevens]

Is the room where the tanks are on some set (and maintained) temp range?

They will actually be outside, covered with 50% shade cloth netting.

 

[FreshyFresh]

If all you are trying to achieve is ~3deg above ambient, that should be a piece of cake. Like said, if you don't want to trust the thermostatic control on the heaters themselves, Google "aquarium heater temperature controller". I've seen them from $35 up. You basically roll the heater's dial up all the way and keep the heater plugged into the temperature controller to maintain the temp you chose on the controller.

 

[pbeemer]

freshy, he needs to have the temps slaved to a moving target (whatever the ambient tank is + 3C). as you say, it should be easy unless the outside is very windy because holding a small tank (lousy surface:mass ratio) to 3 C above ambient is pretty easy. a 50 gallon stock tank should be even easier

it is pretty easy to disable the thermostat in a conventional heater into the "always on" state -- dial the thermostat as high as it will go, which should be well above 95F

i would be a little concerned about how you're going to set up the circulation system in each tank to keep the tank temperatures uniform enough (whatever your spec is) without having so much circulation that both tanks track ambient exactly

 

[Rbishop]

They will actually be outside, covered with 50% shade cloth netting.

Outside year round in CT?