Brown spots on fan leaves.

Soil: Fox Farms Ocean Forest + 25% perlite.
Water: Tap, pH balanced to 6.4, tds meter shows 325ppm
Nutes: Grow big, Big Bloom
Watering Schedule: every 3 days, I give it 1/4 nutes.
Temp: 66-74F
Humidity: 50%
Lights: 5x26w Daylight CFLs

I dont understand what's the problem. Nute lock out but why? My water is always a pH of 6.4-6.6.
I only have one thing to add, the water very quickly jumps in pH, and so before every watering I have to lower the pH.

To clarify my watering schedule, I follow the Fox Farms schedule, I give it 1/2 of the required dose, and I cut that down to 1/4 required dose so I can skip the plain water, and give them nutes on every watering.

nute burn.

im having brown spots... also with same problem ....were u feeding it nutes every watering?? i was.. for 2 weeks ...but now i know is feeding it nutes with the recomended dose ... every other watering not suppose to feed it nutes every watering .. i learnd my leason

I am nute watering it with every watering, but I've cut it down to a 1/4 of the recommended dose. Do you think thats the problem?

More pics.

always try to give it the exact dose, just only everyother, or every 2 waterings

What I would do is leech your medium with water 2-3 times the volume of your container and introduce a mild form of your nutrient solution. Perhaps it is the strain but I would just half the dosage for the fox farming schedule and do the alternate water and feeding. Perhaps the amount of perlite you are adding to an exeptional soil base is retaining and not letting run off some nutrients that you have been building up. Patience it will come around and good luck.

what is the PH of you run off water?

pH tested run off water thats 2 days old, 6.4-6.6.