I made a removable frame from pvc that can be easily slipped over the pump and filter. Then wrapped a tarp over it. If the temperature gets really low I will hang a cord with a 100w bulb under the tarp. alsp have a freeze protection feature built into the timer. I set it for 34. Last nite temps in N Tex reached 32 in places. System worked as designed. Got this morning and pump was running.