Stop your spa from leaking in one simple action. Leak Seal seals minor leaks in surfaces and plumbing without draining your spa, hot tub or swimming pool. Simply pour this unique formula into the water. It can't be simpler than that! Leak Seal has been proven to be highly effective for sealing minor leaks in spas, hot tubs, swimming pools and plumbing. Depending on the size of the leak and the number of gallons, it may be necessary to add Leak Seal more than once.