great job but the only thing I would not of done id put the electric so close to the water just in case you get a blow out off a water pipe fittings or some think like that, I would off put the electrics on the wall at the back far away from the water or out side the room on the outer wall.
but ...

Hi there I have been keeping tropical fish for 25 years on and off and got back in to in four years ago after having a heart attack and it was the best think I have done last year I built a fishroom/shed in my garden, it tuck me six months as I have to tune a summer house in to the fish room and I ...

as been said heat the room i used a wall mounted air heater at 33c this give me 25c/28c tank water depending where the tank is in the room top tank are warmer.

good luck