recently set up my fish tank with a huge plec in and going to be getting some more fish to keep him company so looking for,

a heater
some gravel
maybe some plants etc

you should already have a heater if you have a plec, he'll die in cold water

my friend had him in cold water, plus the tank is in front of the radiator, water is staying at 29c.

The Temp is going to drop at night unless you leave the radiator on all the time?

Plecs are tropical fish,he may be alright at the moment,but he will die/slowly from disease if kept in cold water.

got a heater now. thanks for the advice

Got 3 large healthy gold fish i'd swap for your plec if you don't want him?