Assuming we will drain the pool next April to clean it and then refill with fresh water, is there a downside to leaving the pool without cover? This is an inground concrete freshwater pool. My math shows a complete refill costs about $168 and with the rocketing prices of chlorine and the fact that our pool cover is in bad shape and likely needs replacement (which will be $1,000+), I'm tempted to just leave it open during the winter and then drain it next year.