Exactly PPM's are going to go up because there is now less water and the plant is only taking water, not nutes. So that leaves more nutes in less water. Now I don't know what breeder or pheyno u have but the CK I grew was a nute WHORE!!! I fed her between 800-900. She ate it up and never showed...
At what PPM are u feeding? The tips look to be showing a little burn. And whats the strain? FF can be tricky depending on the strain. Also what is ur PH at?
remember the pistil color is not ur true indicator of maturity. U want to check the trichs. That when u will know for sure if ur plant is ready to harvest...... depending on the type high u are looking for
If u are looking for a more head high u should harvest when your Trichs are cloudy with a little amber, but without seeing the Trichs, I would guess maybe 2 or 3 weeks. If thats the type high u are looking for
I think its possible, but tough. I got a pound and a half off 2 plants in a 4x4 SCROG before. Same SQ footage, But i was growing Critical Mass and Critical Kush