Temperature Trust

[Callum]

In my 180litre there seems to be a temperature problem. I have the Heater set at 23c but the thermometres (not digital) say the tank is 27c!. The heater isn't stuck on I've witnessed it go on and off. But the thermometres seem to be working as well. Which should I trust with the temperature the heater or thermometer?

 

[kewskills]

i never trust the gauge on the heaters, i have seperate thermometers in each tank and the heaters are always incorrect.

 

[tibby25731]

Do you have a spare thermometer? Cos if you put a second one in your tank, and both thermometers show the same, then it is very likely to be the heater that is wrong....

 

[Callum]

I have two of the same in each end of the tank, I've assumed my heaters wrong and plan to adjust it gradually to 24c

 

[MermaidMel]

It's the heater on one hand, but you have to also take into consideration other factors like tank lights, ambient temp, sunlight etc. If you took note of the thermometer at 3am when there's no tank lights, sunlight, heating in the house etc. you will see it drop a couple of degrees in temp. I don't think it's possible to keep a tank at one temp that will never change.

 

[Craster]

It's the heater on one hand, but you have to also take into consideration other factors like tank lights, ambient temp, sunlight etc. If you took note of the thermometer at 3am when there's no tank lights, sunlight, heating in the house etc. you will see it drop a couple of degrees in temp.

Surely when there's no external heat sources, the thermostat on the heater will just kick in more frequently to make up from the loss of heat supplied by lighting etc?

 

[MermaidMel]

It's the heater on one hand, but you have to also take into consideration other factors like tank lights, ambient temp, sunlight etc. If you took note of the thermometer at 3am when there's no tank lights, sunlight, heating in the house etc. you will see it drop a couple of degrees in temp.

Surely when there's no external heat sources, the thermostat on the heater will just kick in more frequently to make up from the loss of heat supplied by lighting etc?

Then why in the summer time do I have to turn to my heater off completely?

 

[OohFeeshy]

Probably because it's got a dodgy thermostat?

Heaters seem pants at getting temperature right, I've had a whole load of different makes and still haven't found a decent one. It's probably easier to rely on ambient room temperature; at least it can't go haywire and poach the fish.

 

[Craster]

It's the heater on one hand, but you have to also take into consideration other factors like tank lights, ambient temp, sunlight etc. If you took note of the thermometer at 3am when there's no tank lights, sunlight, heating in the house etc. you will see it drop a couple of degrees in temp.

Surely when there's no external heat sources, the thermostat on the heater will just kick in more frequently to make up from the loss of heat supplied by lighting etc?

Then why in the summer time do I have to turn to my heater off completely?

I can only guess that the thermostat is broken in your heater! The heater should only kick in when the water temp drops below what's desired.

 

[Callum]

The heater seems to come on and off fine but its maintaining the temperature 27 rather than the selected 23. I have turned it down a bit and will check on it again later

 

[MermaidMel]

It's the heater on one hand, but you have to also take into consideration other factors like tank lights, ambient temp, sunlight etc. If you took note of the thermometer at 3am when there's no tank lights, sunlight, heating in the house etc. you will see it drop a couple of degrees in temp.

Surely when there's no external heat sources, the thermostat on the heater will just kick in more frequently to make up from the loss of heat supplied by lighting etc?

Then why in the summer time do I have to turn to my heater off completely?

I can only guess that the thermostat is broken in your heater! The heater should only kick in when the water temp drops below what's desired.

It's the same with any heater, why do they make coolers and stuff? i don't believe that external heat cannot effect the water.

 

[Evad]

If you have to turn off your heater in the summer to keep it from overheating, then there is something wrong with the heater. The only exceptions I can think of is if you have a heater that is way too big for the tank you are using. In that case the thermostat cannot cycle on/off properly because the tank temp changes too easily. Food for thought.

Back to the original poster. I have yet to ever find a heater that was accurate. I just plug them in and use a digital thermometer to make sure the water temp is where I want it, then I turn the heater down until the light goes off (or in some cases I need to turn it up).

One other thing - make sure you have some water current around the heater - that helps a lot with keep the whole tank an even temp

 

[Mikaila31]

I never trust my heaters thermostat. The heater on my 55gal runs at 73F and the tank is 79F. A heater should keep the tank a stable temperature unless something else is heating up the tank, or the room gets too cold for the heater to cope with. My 55gal stays stable at 79F even when the room temp swings between 59-75F.

 

[OohFeeshy]

It's the same with any heater, why do they make coolers and stuff? i don't believe that external heat cannot effect the water.

Coolers are for when external heat (ie, room temperature or, more usually, powerful lighting) renders water temperature too high, or when the fish species likes water that is particularly cool.

Heaters have an internal thermostat (for example, a bimetallic strip, although I'm not sure if that is what they usually have) that *thereoretically* turn on when the water is below the specified temperature and switches off when it's above it. Thus maintaining the set temperature. But it isn't exactly a great system; the thermostat can easily get stuck in the 'on' position and cook the fish, turn on at the wrong temperatures etc.

 

[Tobigara]

I never trust my heaters thermostat. The heater on my 55gal runs at 73F and the tank is 79F. A heater should keep the tank a stable temperature unless something else is heating up the tank, or the room gets too cold for the heater to cope with. My 55gal stays stable at 79F even when the room temp swings between 59-75F.

i have the same issue in my 55 but the gap is bigger. my heater is turned all the way down to 69-70 degrees but the water temp is a very constant 82.