which test kits to buy?

[smitas5]

OK I was bringing my water for testing to LFS and they found 0 Iodine.. the rest of the parameters were in good range. Now before I start purchasing like crazy (tests and additives), I already know I will change my salt from Instant Ocean to H2Ocean in the next short while.. Should I wait till I change it and see how my water is?
copper stuff is for treatments that I'm planning on my fish, they are in quarantine at this moment and since I can't get copper based stuff, they are in hyposalinity mode now..