Something's wrong with my plant. Please Help!!!

Need some help guys. My leaves are dark green and droopy, leathery looking with yellow tips. I'm about a week into flower and my leaves started looking bad about two weeks ago. It didn't start too bad, but it quickly took a turn for the worse. I have her in a 5 gallon bucket with miracle grow potting soil, no additional nutes to date. 8 light t5 panel I keep 4 inches above canopy, humidity is around 40% and temps between 75 and 80. I water on average every 3 days

First guess was over/under watering or a root problem. All help is appreciated.

Overwatered to me, at 4 inches high ....is too high . lower to within 1-2 inches of plant tips, there are 2 versions of the T5, one at 2 feet long and the other at 4 feet long ...ensure you have the latter if not get another 2 foot long T5, to supply ample light to the grow area..

..not enough perlite in the soil mix, perlite is used to avoid compaction and dilute the 'HOT' soil ...not too late to pot up to a soil ...perlite mix, and water well, allow to recover in a dim room overnight or 1x day

thanks a lot for the quick response vostok. I do have the four foot lights and I will be lowering them and mixing my soil better. thanks again