When do I add weight to the rack - recomp?

I weigh about 154 lbs and am 6'0. I'm still in my first year of weight training but I'm fairly weak and still have a decent gut.

My question is about recomping. If I'm eating under maintenance, how do I know when I should add weight to the rack. Take my squats, for example. I lift at 175 right now and it feels heavy, but I'm not sure how to go about when to properly add weight to the bar. Any pointers or tips would be greatly appreciated!