Nice veeeeery healthy looking leaves. I tend to judge the plant by its leaves. Look for discoloration of the stems, as well as burnt tips, look underneath leaves as well for discolorations, or bugs. Ill also share another one of my secrets. Every week or so, i like to wash my leaves with a super mild concentration of dawndish soap and cold water. Light cant penetrate well through dust, i do this to make sure i absorb as many lumens as possible. Growing inside you are bound to accumulate some dust on your leaves, this way you can help your plant out, and also ensure that your growroom is clean, which helps a lot to keep out bugs, fungus, mold, etc.. Also be sure to dust off your bulbs from time to time with a papertowl. GL seems like you got this under control. Ill post pics of my girl tomorrow if you're interested.