I don't believe coral dips do anything for ich so your best best is to set up a small qt tank specifically for coral and inverts and just make sure every new coral and invert stays in that tank for atleast four weeks
Hyposalinity and copper work 100% if done correctly with hypo being the less stressful on the fish. I personally have used a product called metroplex with good results
Where'd you get your rock and sand I wish mine came with all that. Wow I'm sure I'll ever get my tank that clean again. But come it's a 100g tank you've to go with something bigger than a pair of clowns