no definatly not table salt. it has to be non iodized salt. I use pond salt because its cheaper than aquarium salt and is exactly the same thing. petsmarts have it at a good price. I run about a tablespoon per 10 gallons of water at all times and I have never had a disease. In times of stress most fish do very well at 1 tablespoon per 5 gallons but scaleless fish can be sensitve to this amount. if you are not running any salts I would add a tablespoon for every 10 gallons as a normal regiment. just remember that the salt only leaves when you do water changes so you have to re add salt for the amount of water you removed. It does look like lld to me but i am no expert. and if its going away I would just make sure your water is very clean and see if it clears up.