Winter temp in tanks

[AbbeysDad]

Is there just one heater in the tank and what's the wattage of the heater and what's the size of the tank? under rated?
Also, with the possible exception of external controllers that tend to be very accurate, heater set points are really just a guide. A thermometer or two are always a better measure of water temperature.

 

[Byron]

Have you considered that the temperature those thermometers (post 13) are registering is only at the level in the tank they are positioned? If you move one down close to the substrate, you should find it is cooler, by a degree or more, that at the surface. I always notice this difference when I have to do something at the substrate level during the water change; water stratifies naturally, and fish expect it.

Another thought...aquarium heaters work relative to the external air temperature; the warmer the room the easier/faster the water will be heated. That could be playing into this too.

 

[AquaBarb]

Is there just one heater in the tank and what's the wattage of the heater and what's the size of the tank? under rated?
Also, with the possible exception of external controllers that tend to be very accurate, heater set points are really just a guide. A thermometer or two are always a better measure of water temperature.

Tanks 220 litres and i run a single Tetratec ht 300 w heater. Heaters only about 4 months old and up until the last few days (that im aware of) as kept the temp spot on 25.5c.

Temp as been 26.7 all afternoon but as now dropped to 26.5 now heatings off

 

[AquaBarb]

Have you considered that the temperature those thermometers (post 13) are registering is only at the level in the tank they are positioned? If you move one down close to the substrate, you should find it is cooler, by a degree or more, that at the surface. I always notice this difference when I have to do something at the substrate level during the water change; water stratifies naturally, and fish expect it.

Another thought...aquarium heaters work relative to the external air temperature; the warmer the room the easier/faster the water will be heated. That could be playing into this too.

I do think its the warmth of the room whats making the temp higher in the tank. Problem is ive been using a none digital thermometer since setting the tank back up and it wasnt until i purchased a new digital thermo i realised the water had rinse in temp from how i set the heater adjustment. It just happens the last week the cold nights have come so heating in the house is on longer through the day. (Hoping this is the case and not a faultly heater)

With me not having fish through the winter before i was concerned my odessa might struggle if the temp stayed higher at 26.5 +.

 

[Byron]

I do think its the warmth of the room whats making the temp higher in the tank. Problem is ive been using a none digital thermometer since setting the tank back up and it wasnt until i purchased a new digital thermo i realised the water had rinse in temp from how i set the heater adjustment. It just happens the last week the cold nights have come so heating in the house is on longer through the day. (Hoping this is the case and not a faultly heater)

With me not having fish through the winter before i was concerned my odessa might struggle if the temp stayed higher at 26.5 +.

What is the room temperature at night? I couldn't see this given earlier in this thread. The tank water will not be warmer than the air temperature unless the heater is raising it, so turning down the aquarium heater may solve this?

 

[AquaBarb]

What is the room temperature at night? I couldn't see this given earlier in this thread. The tank water will not be warmer than the air temperature unless the heater is raising it, so turning down the aquarium heater may solve this?

Ive just checked the house heating and its set at 23c so really going of that it shouldnt be making a difference to the tank temp. But the heating went off about 3 hours ago and the temp as come down 0.2. I havent messed with the settings on my tank heater since i purchased it so why would it go up from 25.5 to 26 5 if it wasnt the room temp??

 

[Dan92]

Have you got a spare heater for the tank around, that you could switch in and test?

I have had heaters last months and others last years, the problem with technology is you can never really be certain how long it will give you. My last heater crept up slowly to about 27 before I removed it, but was at 25 for months without any issue.

Could also be that whilst your thermostat in the house is set to a certain temp, that with insulation / bodies in the house etc it is getting slightly warmer. Don't forget also that your aquarium light gives off a lot of heat if you have T5s or T8s, even more so if using a reflector!

 

[AquaBarb]

Have you got a spare heater for the tank around, that you could switch in and test?

I have had heaters last months and others last years, the problem with technology is you can never really be certain how long it will give you. My last heater crept up slowly to about 27 before I removed it, but was at 25 for months without any issue.

Could also be that whilst your thermostat in the house is set to a certain temp, that with insulation / bodies in the house etc it is getting slightly warmer. Don't forget also that your aquarium light gives off a lot of heat if you have T5s or T8s, even more so if using a reflector!

Only spare heater i have is the one i use for my quarantine tank which would be to small for the big tank.

Temps only gone up 1c and seems to be staying within 26.5/26.7 range now. I really throught it might be the heating in the house but expected it to of come down lower during the night. 26.6 when i checked this morning

Not sure what to do really, was just going to monitor it over the coming days and see how it is. Might for peace of mind just purchase a replacement.

 

[seangee]

Most thermostats work on a range rather than an absolute value. So for example a setting of 25 would turn the heater off when it reaches 25, but it won't turn back on until it drops to 24.5. Ideally this range is not too narrow as the heater would not last very long if it turned on and off every 5 minutes.
I use an external controller so I can set the range. I mostly set this to a full degree C

 

[FishGuest5123]

You mentioned a new thermometer. Could it be that. Different heaters can register differently.

 

[AquaBarb]

You mentioned a new thermometer. Could it be that. Different heaters can register differently.

Had a new digital thermometer to read the temp in the tank but the heaters the same one i had from the off. Ive not altered any setting on my heater from when i had the tank running before.

Not sure what it is tbh. Just going to have to watch it closely over the coming days

 

[AquaBarb]

Most thermostats work on a range rather than an absolute value. So for example a setting of 25 would turn the heater off when it reaches 25, but it won't turn back on until it drops to 24.5. Ideally this range is not too narrow as the heater would not last very long if it turned on and off every 5 minutes.
I use an external controller so I can set the range. I mostly set this to a full degree C

Mines set at 25c but for some reason its either not turning of till 26+ or something else is heating the water more

 

[Byron]

Mines set at 25c but for some reason its either not turning of till 26+ or something else is heating the water more

The degree number often is off on aquarium heaters. My Eheim Jager which is the last one I bought some four years ago is set at 20C which keeps the tank water at 24C and has all the time I've had it. I've had heaters previously that do much the same.

Why not just turn the heater setting down a degree?

My earlier comment about room temperature had to do with the ambient room temperature affecting the aquarium heater. The cooler the room the more the heater has to work, and the warmer the room the less. Aquarium heaters are intended to maintain a temperature that is not more than 10 degrees above the ambient room temperature.

 

[AquaBarb]

Yes Byron i understood that thank you. The ambient room temperature is now warmer than it was say a few weeks ago because the cold weather is now here and the central heating in the house is on more. So my heater should be working less.

Just dont understand if my heater turns off when it reaches 25c and the room temp as knocked it up to 26.7 during the day, surely at night when the heatings off the water temp should come back down in the 25's?? Weve had heating on before and my temp always stayed at 25.5.

Ill try turning down to 24c

 

[AquaBarb]

Turned heater down to 24c and the new digital thermometer was still reading 26.6. So i thought id try putting the fluval thermometer i used before in and it read 24.7.

The new thermometer must read alot higher for some reason. Its reading 26.9 in my small tank and i know thats defo 25c

Least i know my heaters ok now. Panic over