If your tank is a month old, you didn't use live rock, nd your dosing everything the store sells, you're in trouble. You should not have those fishin there yet, and a couple should never go in there.
Return the tangs, tank is too small. Return any additives, tank doesn't need them. Find new fish store, you don't need that one.
Don't buy anything else until you ask here or another board. We don't sell stuff here, so our advice is not biased.
You need to slow down. A lot.
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Brad
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