i have a res that is about 4 inches long that i have had for almost a year now. he/she is in a 20long aquarium and has recently stopped eating. i thought this might have something to do with the fact that it has gotten very cold recently. there is no heater in the tank since the room he is in usually stays very hot. since it has been getting cold, i lowered the water level (to only 2 gallons) and i have been leaving his light on 24/7. (its not a heat lamp, just an aquarium hood with an incandescent red bulb. it produces a fair amount of heat.) i do have a heater i can put in there though.
normally i feed flukers aquatic turtle pelletts rolled in nature zone essential vitamins and essential minerals and occasionally some hikari freeze dried shrimp (i cannot get him to take any sort of vegetables.) i also bought him the ectotherm aquatic tutrle yummies which he had absolutely no preference for. (i still have them in the frisge if for some reason they might help.) since he stopped eating i bought some jurassi guard garlic spray. it enticed him once but he only ate one pellet. yesterday i bought the other jurassi guard spary (the banana oil one) and he hasnt responded at all to that. he seems to be acting fine although he did bask all night last night (which is a little unusual)
i also use novaqua and amquel plus to conndition his water (so there are electrolytes in the water from the amquel)
please help me. i will be so upset if i lose him.
here are some picture of him 


