Putting in 20x40 in ground vinyl pool. I would like an automatic pool cleaner that automatically cleans along the bottom, sides, etc, that is safe for vinyl. Also, how do they work? I am not having any kind of special thing put in for a vacuum. I am thinking they must be like a Central Vac in a house and need an outlet? Are there some that don't need any special place to hook them into, and which are the best?