Salinity is low, but the start of suggestions.
With using the API kit, may I suggest, taking a good water sample to a trusted LFS and have them test your water and verify the readings and compare with your API results.
Additionally, I suspect as mention an acclimation possibility. After floating bag for 20 mins to equalize water temp, empty contents into a CLEAN pail or bucket and add a cup of tank water to bucket every 15 mins 5-6 times (1.5) hrs and then give clowns a quick freshwater dip in equal temperature water and scoop them with cup - Not net and release into aquarium.
DO A WATER CHANGE BEFORE ADDING ANOTHER PAIR AND RAISE SALINITY DURING THIS WATER CHANGE.