I highly doubt you need a water heater in Malaysia. I'm guessing the water is
always around upper twenties Celsius already. UVB lighting is needed, unless you
have time to bask your turtle under morning sun every day. Decoration is
optional though, whatever makes the owner happy
Try feeding something else, like mealworm, boiled eggwhite, pellets soaked in tuna
water, etc. Or try to feed separately. Jello method is usually used to entice eating
veggies. Not eating could be caused by new environment. So you might want to
wait a few more days. Good luck!