Welcome to the world of SPS keeping. The Red Sea A+B is a perfectly fine 2-part additive to use. You will want to also test and dose Magnesium. I personally like Brightwell's Magnesium powder, it's a much better value than the liquid supplements out there but does need to be mixed with purified water first before putting it in the tank. Here's a helpful video on 2-parts. Watch, listen, learn: