You can use AHA and BHA together, but its not necessary. Try using AHA in the morning and BHA at night. Remember AHA exfoliates the top of the skin whereas BHA's get deep inside to work inside the pores to combat oily skin, blackheads and helps unclog pores.

I personally use AHA and BHA together. I absolutely have to. It's the only combination that works for my large pores and blackheads in my t-zone. I use Dan's 10% AHA at night, and Ninja Skincare's Salicylic (BHA)in the morning. It serves as an excellent primer for my Everyday Minerals powder foundation. It is the only foundation that doesn't break me out. It only has 3 ingredients. Completely hypoallergenic, non-comodogenic, fragrance free & never tested on animals.
Also, I exfoliate at least 3 days a week! If I don't do this very important step, all the flaking skin blocks my pores & I get more blackheads. I use my Clarisonic, or a gentle buf puff for the face.

Good luck!
Amy