Salt

I have just come across this link which explains the use of salt in freshwater aquariums. The author is a well respected hobbyist in the USA.

http://www.theaquariumwiki.com/The_Salt_of_the_Earth

His first two points are about using table salt - I have often advised against the use of table salt because of the iodine and anti-caking agents it contains, but it had never occurred to me that the amounts are so small that they won't affect the fish adversely.

He goes on to explain why salt should not be routinely added to freshwater tanks. And he does it much better than me