Tip leaves drooping/curling

[NoSalt]

1st time indoor box grow...3'x3'x7'.
Light: 600 hps @ 18-24" from tips
Pots: Smart Pots 2&3 gal.
Soil: Blackgold coco blend
Nutes: Canna coco A&B, Rhizo, Zyme, Boost, PK13/14
water Ph: 6

I'm on day 10 of flower, and the leaves of one of my plants started this rounded drooping/curling at the tips. Other than that everything else seems to be okay. Just looking for somebody with experience who can tell me whats up so I can fix it. Thanx.
-NoSalt.

NoSalt Reviewed by NoSalt on 11-21-2008. Tip leaves drooping/curling 1st time indoor box grow...3'x3'x7'. Light: 600 hps @ 18-24" from tips Pots: Smart Pots 2&3 gal. Soil: Blackgold coco blend Nutes: Canna coco A&B, Rhizo, Zyme, Boost, PK13/14 water Ph: 6 I'm on day 10 of flower, and the leaves of one of my plants started this rounded drooping/curling at the tips. Other than that everything else seems to be okay. Just looking for somebody with experience who can tell me whats up so I can fix it. Thanx. -NoSalt. Rating: 5

[NoSalt]

I forgot to post...
Outake: 4" filter...A/C hood...4" can fan....out.
Intake: 9, 1/2" holes
Day temp: 70-80
Night temp: 60-70

[NoSalt]

Ok so I guess I'm just waiting for Stinky to ride into my post on her golden stallion, to bring me her many fine gifts of wisdom and knowledge, and tell me what i did wrong and how to fix it.
UPDATE!:
I think I should mabey be a little more specific on nutes...so....
Last watering was:
Tap water: Ph around 9
Rhizotonic: 1.5ml/Gal.
Cannazym: 6ml/Gal.
Boost: 8ml/Gal.
Canna coco A&B: 3ml/Gal.
Ph down till water was at 6

Just finally did a PH runoff test, and I know Its bad, just not sure exactly what is the best way to fix it....so...
I took a gallon of tap water(Ph around 9) brought Ph down to 6.5.
Poured it in and grabbed about 2oz. runoff.
Runoff was yellowish in color(similar to color of prepared nute water)
Ph of runoff water was between 5 and 5.5.
Soil Ph: 4.8-5.2 I think.

Anybody know if I should flush with strait tap water(Ph around 9) or bring the ph down to 6.5 or 7 first? HELP! Thanx.
-NoSalt.

[stinkyattic]

Check out the flushing sticky at the top of Problems. Don't flush at pH 9. Use pH 8, flushing with a correct pH Up product, until your runoff reads ~6.4. I don't think your tap water is actually 9; the water utility would not allow that- check your meter calibration.
What is the hardness of your water out of the tap?
How large are the pots your plants are in, and how tall are the plants, and how many main branches/tops per plant?