I don't have a heater in my tank, but our house never gets colder than about 60F. I don't even know what the temp of my tank is because I don't have a thermometer. They can stand a wide range in temps as far as I know, from about 60F-85F or so.
Hello mech i am not sure what you meant by it being 33 deg. You meant outside correct. Here in NJ it 23 deg going down to single digits. I do not heat my shrimp tanks but i heat my house. It currently is 68 deg now. I set the temp during the day when only the dogs are at home at 62 deg and night when i am asleep at 62 deg. I quess the tank temps are arround 65 deg. Summer temps 78 deg.
My temp is 68F.
It was interesting to see the shrimp react to me putting in my thermometer, and later when I removed it. I heard they are drama queens but I had no idea! They all freaked out and swam around all herky jerky.
mine gots 69.5 the lowest and 71.3 the highest no heater. got down to 68.7 with negative temps outside. but i also have a larger volume of water so my temp is a bit more stable.