I am sorry to say that I think you where misled by the first store. That store was looking out for themselves and the quick buck they could make. If they really did you give you that advice, I would recommend you never waste your time or money there again. I'm glad you realized that you needed some more advice and you came to see us.
Putting those three fish in such a new tank may be a disaster. Tomato clowns can be VERY mean and they can get large like the Blue tang. They will need more space than a 30 gallon tank can offer them. I would try to trade them for credit or give them to someone who has room for them. The other clown (I'm assuming an Ocellaris or similar) should be fine in your tank for now.
As far as the Buffer and supplements for the
LR...stop adding them. Adding "stuff" with out knowing how and why will cause you problems.
Do you have Itunes on your computer?
