When to heat

[jmlotl]

Hi all: I've got a 4yo axolotl in a 40 gallon long tank. Due to our (horrible, horrible) landlord, I was obliged to suddenly put the tank on a kind of three-season porch: enclosed, but drafty and only barely heated. With Fluval 207 canister filter and a JBJ chiller in the summer, it can be kept right at sweet spot temperatures. But, now in a bitter cold stretch where I live, I caught the temp dropping to 39ºF one day and resolved just to run a space heater nearby, driving tank temps, at least, north of 55 as it runs. The lotl is active, though its metabolism has perhaps slowed.

But it is quite expensive to heat the little porch, and we have a succession of subzero days on the way. I wondered how low is truly too low for tank temps, and what people in a similar situation might propose as a safe way to heat the tank during that stretch and the rest of the winter, after which we will have moved and resolved this problem. It seems possible that we might want to wrap insulation around the tank just to keep it from getting real bad, anyhow, since I know that can be done.

Anyway, any thoughts would help, and thanks as ever for this resource!

 

[wolfen]

below 10°c/50°f axolotls tend to get more sluggish with colder temperatures causing health issues.
there have/are cases where axolotls have been kept in ponds that have frozen over and been fine although there is no note of pond water temperature at bottom of the pond.
axolotl tolerance range is 4°c/39°f - 24°c/75°f (lowest and highest temperature being harmful to health), ideal temperature is 15°c/59 - 18°c/64°f
easiest type of heater to use would be an aquarium heater although restricted water movement may be an issue and the temperature control would be better using an external controller due to most heaters not having a low enough controller built in (designed for warmer water species).