I've just done my first tests using the API Saltwater test kit, but when it came to the Ammonia test, the solution turned cloudy.
Tried it twice, cloudy both times. Used my girlfriend's Freshwater test kit with my water, cloudy again. Used both kits on the freshwater tank and no issues at all.
The bottom 2-3mm of each test tube of cloudy solution shows a clear colour yellow, 0 Ammonia?
Tried googling "cloudy ammonia test" and found a few post on various forums, mostly about salifert kits, but nothing definitive.