Hey benua,
yeah - they look a little fatigued. Not over-watered, as you are letting it dry out completely before watering.
I would suggest fiddleing with your ventilation a bit...if you are in a space like I am, focus on your outtake fans and not sucking air in. In a small space, it is easier to have a passive intake valve (i.e. a hole in the bottom corner of your tent) and an active outtake vent (i.e. a fan in the top of the box), plus an extra fan oscillating inside to move the air around. This will help bring your humidity down. I was having problems with my humidity and I made the change to a passive intake and my problem was solved.
Here's what I would do:
1) fix humidity with every fix in the book - I even have a tupperware container full of rice, baking soda and salt, to absorb any excess moisture in the air.
2) Flush the plant - on your next water, give it a shit-load of pure water, no nutrients. Make sure that 1/2 of the water you put in to the plant, drains out of the bottom. This is a way to make sure you've done a complete flush.
Once that happens, let it go for a week and see how it reacts. If it seems to perk up, then you know it was the nutrients. If it gets worse, then it's most likely environmental (i.e. humidity). Flushing is a sure-fire way to find out of the issues are due to nutrients/soil or if it is environmental.
Good luck, and feel free to PM with more questions.
-Smacks.