Don't add medicine daily, only when you change the water. So the next time you change the water (probably Friday since you want to change it twice a week while medicating), add 2 drops of aquari-sol and a pinch of salt.
Then next week only add 1 drop of aquari-sol and a pinch of salt when you change the water. Once the velvet clears up, you can still add 1 drop aquari-sol as a preventative and you can go back to changing his water 1 time a week. Definately keep adding a pinch of salt during his water changes though. I hope that's a clear enough explanation.
Alexa
Then next week only add 1 drop of aquari-sol and a pinch of salt when you change the water. Once the velvet clears up, you can still add 1 drop aquari-sol as a preventative and you can go back to changing his water 1 time a week. Definately keep adding a pinch of salt during his water changes though. I hope that's a clear enough explanation.
Alexa