Strange request... LOW Tank Temperature required!

[Stickleback]

Apologies, I have asked this in the Coldwater section, but just realised it might be equipment related.

Can anyone advise me if it is possible to maintain the temperature of an aquarium at around 8 degrees celsius?

My children have kept some native fish, sticklebacks, and I think maybe one is a Stone Loach, for 4 months now, and they are taking a great interest in it.

If you are interested, they have a YT channel, and here is one of their Stickleback videos

My problem is, they are keeping the tank in their own shed, which isn't insulated, and I am slightly worried that now that we are coming into winter here in Northern Ireland, the shed might get down near freezing point.

I think they might thrive better at around 8-10° Celsius 46-50° F

The only aquarium heaters I can find have a lower limit of 18° C, 64°F

Could a normal aquarium heater plugged into a standalone thermostat work at the lower temperatures?

Has anyone else had this problem? Or has anyone any advice?

Thanks in advance

[charliebankston]

Here is a basic chart that another knowledgeable member posted on a different thread

[charliebankston]

It's in Fahrenheit tho, but you can convert. If your shed is 5 degrees Celsius, than a heater of appropriate size will only raise the water temp by the corresponding amount. Not to 76 F for example

[Stickleback]

Originally Posted by charliebankston

It's in Fahrenheit tho, but you can convert. If your shed is 5 degrees Celsius, than a heater of appropriate size will only raise the water temp by the corresponding amount. Not to 76 F for example

Thanks for the reply Charlie.

It is possible that this shed will get even colder than that. I am trying to decide on a thermometer that will be accurate at such low temperatures.

Am I right in thinking that in the 15g tank with an ambient temperature of 0-5 would need around 75w heater?

[charliebankston]

Originally Posted by Stickleback

Thanks for the reply Charlie.



It is possible that this shed will get even colder than that. I am trying to decide on a thermometer that will be accurate at such low temperatures.



Am I right in thinking that in the 15g tank with an ambient temperature of 0-5 would need around 75w heater?

That sounds about right. It would still keep your water cold, but not frozen, lol. You can always adjust the thermostat and play with it until you find your optimal temp

[Stickleback]

I'm now not sure I have worked that out right.

That chart is Fahrenheit, and the 3 columns are to increase above ambient by 5, 10, 15 F

I'm thinking I need to rise from 35°f to 50°f, which is a jump of 15°f required.... I'm guessing now 100w minimum?

I need to get the ambient temp measured asap.

[charliebankston]

If in between, I'd round up on the wattage, because you can always turn the heater down to low

[fishwonder]

Try here for information that may help.
https://oemheaters.com/topic/immersion-wattage

[charliebankston]

Originally Posted by fishwonder

Try here for information that may help.
https://oemheaters.com/topic/immersion-wattage

That's a cool little built in formula

[charliebankston]

Just quickly plugging some numbers in, and guessing at the air temp in the shed, looks like 110 watt. Like I said, if it were me, I'd prob just round up and adjust the thermostat on a 150 watt

[Stickleback]

Originally Posted by charliebankston

If in between, I'd round up on the wattage, because you can always turn the heater down to low

Good thinking... it would be under less stress too.

Originally Posted by fishwonder

Try here for information that may help.
https://oemheaters.com/topic/immersion-wattage

Thanks.... That is a cool calculator... that must be for domestic or industrial usage.... the theory might well be the same.

The time to reach the desired temperature makes a massive difference to the wattage required.

Does anyone know of any aquarium heaters that do not have a thermostat built in? I have seen a titanium one on Amazon, but the smallest I can see is 300watts, and costs a small fortune

I'm thinking of investing in an external thermostat and probe, as they go way down in temperature.

I think it is likely that they might well survive very low temps, as they do in tiny streams in the wild, but I would rather let my kids see the importance of helping their fish to thrive, and not just survive.

[Stickleback]

Originally Posted by Stickleback

Does anyone know of any aquarium heaters that do not have a thermostat built in? I have seen a titanium one on Amazon, but the smallest I can see is 300watts, and costs a small fortune

Or would a typical built-in stat heater be ok, it would just never reach it's minimum temp?

[fishwonder]

Originally Posted by Stickleback

Does anyone know of any aquarium heaters that do not have a thermostat built in? I have seen a titanium one on Amazon, but the smallest I can see is 300watts, and costs a small fortune

I'm thinking of investing in an external thermostat and probe, as they go way down in temperature.

I think it is likely that they might well survive very low temps, as they do in tiny streams in the wild, but I would rather let my kids see the importance of helping their fish to thrive, and not just survive.

Will this work?
https://www.amazon.com/Inkbird-All-P...WKGE1WCWQ77RF6

• Output: 2 Relays
• Temperature Measuring Range: -58~210°F / -50~99°C
• Resolution: 0.1°F / 0.1°C
• Accuracy: ±2°F (-58~160°F) / ±1°C (-50~70°C)
• Power Supply: 110VAC 50Hz/60Hz
• Power Consumption: 3W
• Sensor: NTC Sensor

[Stickleback]

Originally Posted by fishwonder

Will this work?
https://www.amazon.com/Inkbird-All-P...WKGE1WCWQ77RF6

• Output: 2 Relays
• Temperature Measuring Range: -58~210°F / -50~99°C
• Resolution: 0.1°F / 0.1°C
• Accuracy: ±2°F (-58~160°F) / ±1°C (-50~70°C)
• Power Supply: 110VAC 50Hz/60Hz
• Power Consumption: 3W
• Sensor: NTC Sensor

Yes, I've seen those, they look ideal, and good value for money, I'll probably go with something like this. Really brilliant! Thanks!

My real question now, is whether it would work ok with a typical aquarium heater, with a built in thermostat, as it would never reach the minimum setting on the heater, when controlled by the external thermostat.

I have been looking for a heater without the built in thermostat, but so far, the only ones I have found are 300w and 600w, much too big for this little tank.

[fishwonder]

Originally Posted by Stickleback

My real question now, is whether it would work ok with a typical aquarium heater, with a built in thermostat, as it would never reach the minimum setting on the heater, when controlled by the external thermostat.

I don't think that would be a problem. The unit will turn on and off the heater using it's sensor. Your heater will always be on since the water is so cold, the contacts will be closed all the time trying to heat. When the units sensor reaches the set temperature it will shut off the heater.

[Stickleback]

Originally Posted by fishwonder

I don't think that would be a problem. The unit will turn on and off the heater using it's sensor. Your heater will always be on since the water is so cold, the contacts will be closed all the time trying to heat. When the units sensor reaches the set temperature it will shut off the heater.

Thanks FW.... that's reassuring! I'll probably just go with that

[ale170]

easiest thing to do is buy an aquarium chiller but the most practicle for a big tank or a hobbiest is get a fridge, drill a hole in the side and fill it with tubing, and use an aquarium powerhead to cycle water through the hosing which is chilled in the fridge. a second hole will release the hose and cold water can exit into the tank

[Stickleback]

Thanks all for your advice! I ended up going for an Eheim heater 150w, and an Inkbird temperature controller, allowing it to maintain 8 to 10°C easily, which seems to be the ideal temperature for the Sticklebacks.

[charliebankston]

Great! Congrats