Browning tips usually mean overfeeding, or there is a nutrient buildup from not proper drainage.

Nute buildup happens when proper drainage isn't there. Like, when you water, and no water comes out of the bottom of the pot, that will cause a buildup of nutes for example.

You said heat isn't the problem, and by the temps you gave it shouldn't be, unless the top is too close to the lights, or are touching the lights, that will happen.

I'd ease up on the nutes for the next few waterings and see what happens, because by the sounds of it, it is getting too much fert.
Nochowderforyou Reviewed by Nochowderforyou on . Help--brown leaf tips Hi everyone. So I am doing an indoor grow, my growlog is in my sig, but to bring everyone up to speed here is where im at: 2 girls, lowryders, day 30, both have been looking really really good so far. im feeding with watered mixed with pure blend pro bloom for soil. and i am also using a bit of molasses. pH of my water is around 6.6 or so. temps are at 78°F, humidity at 40-50%. For a little while ive noticed a few leafs starting to brown just at the very tip of the leaf. the Rating: 5