My pond is a small 150G garden pond on my patio under a patio cover. I live in Texas so we only get freezing weather usually at end of December through end of February and then only intermittently. My pond is only 18” deep. Is there anything I need to do to prepare for colder months? At what temp do you stop feeding your fish? I have one common, comet, and Shubunkin in my pond. Thanks in advance!