What Size Heater for a 40g?

AquaticQueen

Hi, I was wondering what size heater I would need for a 40g tote/storage bin. The bin would have a somewhat similar footprint to a 40g breeder. I would need the temperature of the water to be at 77-80 F (for guppy fry) with the outside temperature being about 62-64 F because it will be located in my unheated basement (that won't be an issue, btw, will it?) I entered it into Fishlore's heater size calculator and it said 300 watts, which seems a bit excessive to me because everything I've read says 200 watts. I really don't want to mess anything up and I don't know who to listen to. Help!
 

BigManAquatics

I have a 200watt in my 45 that does quite well.
 

AquaticQueen

With the temperature of my basement taken into account, do you think a 250 watt would work?
 

Dunk2

Hi, I was wondering what size heater I would need for a 40g tote/storage bin. The bin would have a somewhat similar footprint to a 40g breeder. I would need the temperature of the water to be at 77-80 F (for guppy fry) with the outside temperature being about 62-64 F because it will be located in my unheated basement (that won't be an issue, btw, will it?) I entered it into Fishlore's heater size calculator and it said 300 watts, which seems a bit excessive to me because everything I've read says 200 watts. I really don't want to mess anything up and I don't know who to listen to. Help!
Sorry to complicate your life :), but I’d go with 2 150W or even 2 200W heaters.

Gives you some duplication and neither one would need to work as hard to heat the water.
 

RayClem

The standard recommendation for a 40 gallon tank /bin would be 150-200 watts based on a typical room temperature. However, that is not the situation you have, especially if your bin will be sitting directly on a cold basement floor in winter. I have a 40 gallon breeder tank in the basement with similar requirements to yours.

In your situation, you need 300 watts. However, I agree with Dunk2 that the best solution is not a single 300 watt heater, but two heaters totalling 300-400 watts.

Sooner or later, all heaters will fail. The two most common failure modes are: the heater will stick in full on mode or the heater will stick in off mode. If you have a single heater and it sticks in off mode, your water temperature will drop to 62-64 degrees and the fish are likely to get sick. If a single heater sticks in on mode, that might not be a huge problem in winter, but in summer, the water temperature might get hot enough to kill the fish. If you have two heaters and one of them fails in either mode, the tank will still say within a reasonable range.

Another good reason for two heaters is that you won't have the thermal gradients in the tank that you would have with only one heater. Since this tank is for fry, you do not want strong water flow that would be needed to eliminate these gradients.
 

AquaticQueen

Sorry to complicate your life :), but I’d go with 2 150W or even 2 200W heaters.

Gives you some duplication and neither one would need to work as hard to heat the water.
The standard recommendation for a 40 gallon tank /bin would be 150-200 watts based on a typical room temperature. However, that is not the situation you have, especially if your bin will be sitting directly on a cold basement floor in winter. I have a 40 gallon breeder tank in the basement with similar requirements to yours.

In your situation, you need 300 watts. However, I agree with Dunk2 that the best solution is not a single 300 watt heater, but two heaters totalling 300-400 watts.

Sooner or later, all heaters will fail. The two most common failure modes are: the heater will stick in full on mode or the heater will stick in off mode. If you have a single heater and it sticks in off mode, your water temperature will drop to 62-64 degrees and the fish are likely to get sick. If a single heater sticks in on mode, that might not be a hauge problem in winter, but in summer, the water temperature might get hot enough to kill the fish. If you have two heaters and one of them fails in either mode, the tank will still say within a reasonable range.

Another good reason for two heaters is that you won't have the thermal gradients in the tank that you would have with only one heater. Since this tank is for fry, you do not want strong water flow that would be needed to eliminate these gradients.
Thanks for the responses. Got it. 2 heaters. I do have a 50 watt heater that I am currently not using though. Is there potentially anyway that I could use that?
 

RayClem

Yes you could use the 50 watt heater in combination with a 250 watt heater. However, if the 250 watt heater fails to come on in winter, the tank is going to get cold. The 50 watt heater won't be of much help.

If money is an issue, start off with the 250-300 watt / 50 watt combo and then replace the 50 watt heater with a 150-200 watt heater when you are able.

Heaters do not have to be expensive. I have used a lot of heaters over the 61 years I have kept aquariums. Some have been cheap, some have been expensive. They all fail sooner or later. My latest acquisitions have been Via Aqua heaters. They seem to be as good as many expensive heaters I have owned.

https://www.amazon.com/ViaAqua-200-Watt-Quartz-Submersible-Thermostat/dp/B00513MZ40/
 

AquaticQueen

Okay, I think I'm just going to go for 2 200 watt heaters. Thanks for all the responses, guys!
 

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