Probably low on refrigerant.I would not put leak solution in my system.Find the leak and repair. If it is an older system 15 years or older, there is a chance the evaporator or a coil is leaking.Most older coils ran the tubes through steel sheets where the U tubes are brazed in.Over years the coil will develope leaks where the tubes go thru the steel sheets .Coil will have to be replaced if that is the leak source. $700. to $800. job or more.