if i got a RES and/or an eastern painted turtle and i had a light with 80-90 degree basking spot do i need a heater? or will it just be a good investment for the winter? NOTE: my tank is only 25 gallons it is only a temporary!
A good basking spot between 85-99f should be plenty and avoid the need for a heater. You live in Connecticut so ambient temp unless you have a crazy air conditioner should be fine for an eastern painted. Keep in mind though, you want the water temp to be 75-80max during the summer. If it is a slider then you want to be able to maintain the water temp around 75f.