Is your Bestway Lay-Z-Spa AirJet or HydroJet pump leaking from the Air Blower One Way Valve Assembly?  This is caused when the lower mushroom valve perishes, water can escape from the spa and leak from the drain valve.
The mushroom valve assembly is universal across all AirJet and HydroJet pumps, it is only the original Premium Spa pump with the built in filter that will be incompatible with our kit.