Differences in Salt?

[FishPower]

This is the salt you want to use for freshwater tanks

http://www.mortonsalt.com/products/watersoftner/white-crystal-solar.html

40lb bag for 5$ at home depot for me haha

Morton even says its safe for aquatic use

http://www.mortonsalt.com/faqs/index.html#q8

^ read Number 8

hope this helps your ich problem and also save you a lot of green haha
and i have been using this product for a couple of months with no problems