Can you empty a vinyl pool and patch a hole then refill the pool without doing anything else to it?
Yes you can but you want to balance your chemicals Even Better! You don't have to drain the pool to patch it at all, unless it's a ghastly large hole. The local pool store should offer an "underwater" vinyl patch repair kit for about $10. The patch can be prepared and epoxy/adhesive applied above water and then placed on the hole UNDER the water! No need to empty and dry out the pool at all! I was able to do this when my brand new 12' x 3' Quick Set pool showed a leak as soon as it was filled!