I have a ~600 gallon gunnite inground tub that came with the house I bought. Until this fall we have not used it other than to keep water running through it and closing it with the attached pool. This season we are considering keeping it open and I have a few questions. Background. We live in Oklahoma City. Temps drop into the low 20s sometimes teens Dec - Jan. and are in the mid 20s to low 30s starting November and ending after February. I have a temp sensor to turn the pump on. I have 2 pumps, one for the filter (without a temp sensor) and one smaller one for the jets (with a temp sensor), so I know when the temp drops below freezing I am going to have to have both running.
How much does it cost, if I keep a thick spa cover on the pool at all times, to keep it heated and running? I am probably going to keep it at 55 degrees covered until I want to use it Are we talking about $~$50 a month? If we use it a lot I will keep it around 75 degrees covered.