Kent Marine Essential Elements

[anglfish]

My Cleaner Shrimp seems to be molting every two weeks (has done it three times in the last 6 weeks), so I was wondering whether to supplement Iodine. I do water changes every 10 - 14 days and use Instant Ocean. I read that too much Iodine kills all bacteria which of course I don't like to do. I couldn't find an Iodine test kit so I'm not even sure at what level I am right now.
I was wondering whether anyone had some experience on Kent Marine Essential Elements. Can it be used on a regular base even without testing trace minerals beforehand? (the bottle says yes but I'm not trusting that )

Any advice will be greatly appreciated.

Thanx Angela