I was wondering if there is any reason we couldn't fill the pool with the cover still on? The rationale being that we aren't quite ready to remove the cover/start the filter running, but figured we'd be a step ahead of the game if the pool is already filled once we do open. Thought if we have some warm days before opening, the water might have a chance to start warming as well, etc. Are there any downsides to doing this that we're not thinking of by chance? Thanks!