leaf-tip curling down 7th week of bud

I have an Indica, similar to Big Bud thats almost ready. The bud production has seemed to slow down quite a bit, and although it has a good 2 oz's at least, it seems like its stunting.

I did a flush about a month ago, but probably got over zelous as I used about 15 Liters to try and flush it good, but probably caused over-watering issues.

The plant is all nice and green, yet about 5% of the leaves have yellow rust like spots, and drying tips that crumble. Even some of the canopy leaves are getting kind of winkled and about 75% of all leaves have curled their tips recently. Its been about 4 days since she got fed and it might just be signs of thirst or that its killing off leaves since its almost done flowering.

About 15% of Pistils/hairs are red, and this one got potted with some MG premium potting soil (back to sunshine mix). Now my waters PH is 7.4-8 but I for the first time checked the water with nutes and the PH is 6.6.

I did a cheap run off test, where I poured straight 7.7PH water along the side of the pot and collected 7.7-7.8 PH run-off. Now I don't know if I should do a better test, or try to bring the PH down. I've managed to get away without bothering with PH so far and I plan on going to DCW after my next 3 are done in 7 weeks.

From what I've read it could either be a Potasium (K) deficientcy, Slight over watering, or from cold roots. The soil is around 50 degrees F, and I tried using the ballast to heat it up a bit, but its too scary. I have them off the ground in a garage, but its been pretty cold lately.

I'd post a pic, but my camera doesnt do Macro, and I have a bad experiance with taking pics of plants. Bad Mojo for me. Now I'm not panicing, but I'm watching it closely and if I see it start to burn up or wilt big time I'm chopping the buds before they go bad.

I'm giving them "Dr Hornby Big Bud", Carbo-blast, Super-B, and 7ml/1L part 3, and 3ml/L part 2. I haven't had any issues at all besides this, and my temps are 60-70 F and lots of ventalation. maybe a bit low on humidity but I mist them twice a day.

I've also noticed the leaves are kinda dry and easily broken compared to the younger plants, more so on the huge sun-leaves. I've seen some small yellow spots on the leaves, but it maybe from water drops, although I suspect something else.

It sucks if its K deficientcy, since I don't know if I should bother trying to fix it, or just flush the plant. It has to be fed soon either way, and I'm still on the fence if I should give it, its normal food.

Please help.

 

I should make it clear the the plant does not appear sick, or seriously stressed. I read that curled down tips from over-watering mean the plant is trying to retain moisture. Now I have been taking a bud off her now and then, about 6 total. That may cause a plant to think it needs to try and retain water I suppose.

What I'm more concered about it bud, although since I've been checking on her about 20 times a day now, I maybe worried for nothing. Although she's about 4' tall and I was expecting say 4 Oz's it doesn't look like it will make it. Especially since I'm broke and have no smoke. Do'h

 

ya, overfeeding is likely, since I just bumped them up to the last feed cycle, 7/3. The bud is ripening on the canopy nicely and it gets you quite high, but I'd expect more bud then I can see it producing.