I recommend alkaline items.

Hmm, regarding pH—that concentration—I recommend alkaline products. Mildly acidic products are gaining popularity these days, but I actually recommend alkaline products more. That is because I believe alkaline is actually better for acne-prone skin. However, since this varies from person to person, please do not blindly trust this advice. Still, if you have been using only mildly acidic products and feel they don't suit your skin, I think giving this a try would be a good choice. I recommend using a mildly acidic foam cleanser. You can find them by searching on Naver.