What is growing on my plants?

I'm currently dealing with thrips but this damage doesn't seem like it's thrips. Anyone know what I should do to clean them up? A few of them look like the beginning stages of whatever it is so I want to try and save them! Could it be too much fertilizer? Ive been getting a lot better with my plants but there's so many issues that can happen! I don't think the fertilizer I'm using is the best and I would like a better recommendation.I check and water my plants once a week. Light is set for 12 hours.