The Long Island Sound water is very low on salt and some artificial salt needs to be added.
I would strain it as soon as you get hime or at the beach for the tiny jellyfish and other plankton that will just die in your tank.
Of course the temp there is probably in the fiftees but I don't have to tell you how to raise the temp.
I personally have never heard of anyone on any forum having a problem with NSW.
As Chris said it is a little of a pain to get and I usually collect it when I am going to the sea for some other reason. I am going to montauk this week so I won't pass up an opportunity to collect 10 gallons.