I'm not too fond of salt itself in tanks. Each fish is different.
I will not do water changes right now, as it will just take out most of the treatment. It's not a very "large" tank afterall.
(48 litres)
I will, however, do them after the second treatment. This I think will do much of a better job and thus add more treatment after the water change has been made. :)
(That's just how I like to think it will work)