4 weeks into flowering, may need some help

I am a first time grower, growing 3 female plants from seed, vegged for 40 days and today marks the end of week 4 of flowering. In the last two days most of my larger fan leaves have turned yellow and some are beginning to get brown spots.

SETUP - 16 -27 WATT CFLS
4 - 17 WATT T-5'S AS SIDE LIGHTING

USING PROMIX FOR MY GROW MEDIUM

Vegged using fox farm grow big nutes and followed directions on label to the number

Flowering using fox farm big bloom as directed on label.

Currently watering only when dry - every 6 or 7 days and had been folar feeding lightly every other day since I began the grow until the last week when I stopped the folar feeding

Up to this point I have had no issues - some stretch due to christmas travel and a vacation - had to raise the lights a bit.

Please let me know what you think.

please, someone give me some guidance here.....is it root bound issue perhaps, nute lock up......I need some advice before my baby's get worse. I have fans blowing on the plants when lights are on. Temps range from 70 up to a max of 80...humidity is average about 40 percent. My ph is at 6.8= this has never changed since day one....I could really use some advice or is this just normal

give the ones that look the worst a good flushing of regular Ph water.

Looks like the black spots are bug trails. Dish sopa and some water in a spray bottle and spray the bottoms of the leaves.

are you using anthing as reflective material

no reflective material per say, I am growing in an old wardrobe that I converted...I did paint the entire inside flat white....I don't think its bugs as someone has mentioned, looked with my magnifying glass and can't find any evidence of critters.

yea on my last grow my plants did the same thing and no1 could explain why so i had to wait it out and i just kept budding them and they budded without dying sorry i dont have a explanation

Thanks for the feedback, I think I will give the girls a good flush and see what happens...did you loss the fan leaves pretty early on, How long did you flower them for....like I said this is my first grow and I have gotten this far with our any issues - but this far in I don't want to blow it!!

about the same time it was my first grow to and had no problems until that...........i never lost the fan leaves they jus got brown spots then evenually the tips got brown and i trimmed them and it was fine they budded nicely

still seeking feedback on this issue - any of you old timers got any good advice for me.

still looking for some advice on the issues with my plants.....the large fan leaves looked almost bright yellow when I left for work today...PICUTRES INCLUDED AT BEGINNING OF MY POST.

Water more often and add some nutes with Nitrogen.

OK, went ahead and gave them a little flush last night and then hit them with some quarter strength veg. nutes...they were looking a little better this morning. I just don't understand why the only leaves that are changing are the large fan leaves. I understand that the chloro is being pulled out of them and used up but should the other leaves begin to do this as well....once again first time grower so I have never been down this road before.

On another note - I have read a lot about flushing a few weeks out from harvest and then just watering with no nutes etc.....How in the world do I know when I am approx. two weeks from harvest...my buds are growing really fast right now and I am just starting to get a few red hairs on them.

just checked out your grow JN811 - nice work. I doubt I will get the kind of results you had since I am flowering with a shit ton of CFL'S but your smoke looks great. How long start to finish did you let those babies go before harvesting?

It's hard to tell if there is a problem with fan leaves nearly through flowering. You ain't ready for harvest, I'd wait atleast another few weeks.
Also it is completely normal for the larger fan leaves to lose their colour and turn yellow durring the flowering stage. The plant is after all putting more of
it's resources into bud production.

Thanks for the input SCHWARTS -

I added a little home brew CO2 today over lunch - hope that gives my girls a little more umphhhhhhh. I will chill with worrying about those fan leaves so much. Would I be crazy at this point to repot into larger pots?

Repottin' at this point is pretty risky, however not impossible. From what I can see in your pictures, those plants could definatley use bigger pots. I wouldn't be surprised if they are root bound. If you repot now I'd made sure you do it just before lights on, be extreamly careful! Hold the base of the stem, if you can turn it on its side, shake the pot to get the root ball out undamaged. Do not pull on the stem, you will destroy the delicate root system. ALSO, do it in very low light, high intense light can damage exposed roots. I hope it helps, good luck if you decide to repot!

theyre still growing. Im on day 60 something of flowering. Giving them another couple weeks.

I transplanted mine during flowering and caused them to have shock for a few days, but after they looked a lot better. You have quite a while until you are done, Id say 5+ weeks. Add some nitrogen to your next watering. If you decide to transplant be very careful. I really try to flush as little as possible because it I believe it causes shock. I gave mine a light flush about a week and a half ago, now im just using regular water to feed for the next few weeks.

fox farm is a 3 part nute system

I repotted my worst looking plant on Saturday and she is all ready looking happier. Not sure if my little CO2 mix is making a big difference or not but I have noticed that since I put it my cabinet my avg. temp has increased about 6 degrees - is that normal? It is making all kinds of CO2 bubbles so that must be good.