Tank Wont Cool Down?

[star4]

I am trying to lower the temperature on my 300l tank. I thought simple just lower the thermostat on the heater, did that the temperature is still reading 27, so I have changed the heater for another one just in case its faulty and is stuck on 27, but although the other heater is also set at 22 the tank is still reading 27?. The tank is due a waterchange tonight, I am wondering weather to add cooler water?

 

[BethK]

I'm assuming that cooling down is the same as heating up, in the sense that it can take a couple of days to settle?

 

[jacko32]

I am trying to lower the temperature on my 300l tank. I thought simple just lower the thermostat on the heater, did that the temperature is still reading 27, so I have changed the heater for another one just in case its faulty and is stuck on 27, but although the other heater is also set at 22 the tank is still reading 27?. The tank is due a waterchange tonight, I am wondering weather to add cooler water?

i add cooler water when i do water changes obviously not massively lower just around a degree
a 300ltr tank will take quite a while to cool down say maybe 1 degree an hour

 

[dave_oddballs]

bigger tanks will take a while to cool down, you have to also take into consideration the room temperature, if there is say 7 degree celcius difference between room temp. and tank temp. its not going to lower the tanks temp. very quickly. and also take into consideration the heat off the lights and/or other equipment, by doing a water change with cooler water it should knock it down quicker but as you'd know, don't lower it too quickly, unless of course there is no fish in there in which case it wouldn't matter as much.

 

[meguro]

try putting multiple thermometers in this tank to check that the one ur using is fairly accurate

 

[star4]

Sorry should of said when I turned the first heater down I left it 2 days, the second heater I put in yesterday (switching the first one off). Going to leave the lights off see if that makes any difference.

Thanks for your replies.

 

[rdp50734]

sounds silly but what is your room temperature?

 

[star4]

room temerature is about 18-20 (back door keeps being opened and closed kids!) surley the tank next to is isnt making a difference, that temperature is 27 (usually I cannot find the thermometer in there again the plec keeps pinching it). I have a 400l tank next to the 300l tank?