Black neon tetra in unheated tank?

[juhason]

Sorry for the missunderstanding. Just out of curiousity, which would be your favourite fish?

The fish is called rainbow shiner, when they breed their colors are insane. But here in northern US its a bit hard to find someone who sells them. They are from southeaster US.

 

[juhason]

I second the choice of the external heater, whilst its true they tend to be more expensive but the ease of access and hidden from view makes it a nice choice to have.

https://www.amazon.co.uk/dp/B003ZGGH08/?tag=

Thats just one example from Hydor, which is a reasonable brand as far as I know from other members, be sure to get the right sized one for your tank size as well as the correct on for the external hose size as well, a all too common mistake to make, not checking the hose size specs before purchasing.

Not sure if you'd have the same problem re the electric extension cord so you can plug in this heater though if you decide to go for one.
Unless you can hide the cord wire along the edge of the room tucked into carpet edging and behind cupbards and drawers units sort of thing to eliminate seeing the wiring, just depends on your room layout and where the tank is etc etc. Common sense really.
(Thats what I did once before, helps to hide the wire, I am a little OCD when it comes to wiring, I HATE seeing wires going from lamps, tv's etc and of course fish tanks, wiring HAS to be hidden away as best as possible otherwise drives me nuts heh, but thats just me.)

Thanks for the link! That is a bit pricey but I can save up for it. Does putting a regular heater in there work?
Also yes I am the same about exposed wires! Always have been lol