I have the same looking chlorosis on the tips of my larger fan leaves, also.. I fed them nutes with one watering but it didnt change.. I just tried flushed them for a second time with just water.. I hope it goes away.. It's really annoying.. The thing is, its so tough to decipher between nute deficiancy or over ferting... :-/
It is now day 25 and my plant have all gotten huge. A lot of new branches are forming, and calyx development is being shown, but not mature enough to clearly show sex. My biggest is now 24 inches at day 25! I really can't wait for this yield. My humidity is perfect at 75%. Pics should be up soon!
The praying of the leaves in picture 4 and your yellowing tips and margins are due to heat stress. Lower the temps in the room and the yellowing/praying will stop.
its overfertilization.....dont worry yet...its not that bad....but the next time you give nutrients mix it in a mister and mist the nutrients onto leaves not soil