i wouldn't add any more salt,the only thing you need is dechlorinator
when you do a water change,the salt is no good.
for now if you have a small net you can skim the sand foam from the top of the water,
if you are really fed up,and as it's only a 10glln empty it,wash the sand until you really
are sure your arms won't drop off lol then re fill,perhaps lay a flat stone on the bottom
of the tank so the water won't disturb the sand,and put any decoration back in place as
carefully and slowly as possible,this will help reduce the sand storm.
hth