What is this white stuff growing on my tank glass?

At first I thought they were water spots on the glass until I saw them sway with the current in the water. It’s white and slimy and I’m afraid it could be a fungus of some sort. I’ve been treating the tank with Melafix every day for prevention from adding new fish plus I have about 4 – 5 tablespoons of aquarium salt. I shouldn’t have fungus growing. I am about to do a water change since I’ve had a spike in nitrites. I thought also it could possibly be the start of algae growth..but I haven’t cycled my tank yet so I don’t think that’s it either. My fish don’t seem stressed and nothing is growing on them.