Leaves are curling, drooping and twisting at the tips - Any suggestions?

[BlueSpruce]

9th week since planted indoors and 4th week of flowering and my one pant is really not looking good. I have three plants under a 600 watt digilux HPS bulb ,And an xtrasun air cooled hood I have had some heat issues but they have been corrected as of a couple of weeks after vegging .I vegged with a digilux 600 MH bulb that I started the first week at 50% power than 75% then to 100% power on my nanolux digital ballast. I'm using a carbon filter and two fans inside the 4x4x8 room.My PH is at 7.1 on the plant above and i have been feeding them with Botanicare CNS17 bloom for the last 4 weeks 2-2-3. I vegged them with the Botanicare CNS17 grow 3-1-2. I feed them every seven days w/nutrients and water in between as needed. my other plants are showing the PH at 6.5 and 6.9 .

 

[BlueSpruce]

 

[zBRiCKz]

Curling and twisting is signs of ph fluctuation.

 

[NuttyProfessor]

natural light pictures would be helpful ,

 

[lexort420]

Probably its ph being too high causing lockout cause it also sounds like mag deficiency cause leaves curl and twist when thats locked out too. But im sure your problem started with the ph then was compounded from there

 

[BlueSpruce]

YEAH, They are not yellowing yet maybe one or two bottom leaves . the color is off on the camera and the hps light was on . i'll try and get some natural light pics.

 

[TheCuteOne]

Good plants anyway

 

[BlueSpruce]

I think you are probably right I have been growing without a ph tester for a few weeks and I just bought a new one ,and the plant that is looking the worst is above 7.0 Its at 7.4 I typed in 7.1 By mistake . In fact without disturbing the roots i put the monitor in a few different spots and depths in the soil and one reading was at close to 8.0. a far cry from 6.5 or even 7.0. I guess on my next feed I should use only water or should I buy the Ph solution . I was thinking ust A good flush will work

 

[BlueSpruce]

Thanks . The buds are starting to take off>