The most common harmful bugs (Mites!) and many others you can actually get rid of easily. Get "insecticidal soap" and Neem oil, and make a mix. Then spray your plants with it. This has double benefits: The insecticidal soap kills aphids (mites etc.) on contact, the Neem acts as a repellent and also helps with your plants resistances.
This is 100% natural and safe, in fact the insecticidal soap turns into fertilizer (potash)..so safe you can even spray preventively so that bugs don't even appear. Just don't spray directly on buds in flowering. I am using this for a long time already, no need for chemicals or whatsoever. Ah,and the Neem also helps reduce risk for mold etc.