]Boy, I need to take a nap. Drank too much coffee and can't sleep.
Anyway, regarding your question, it looks like she is in flower. This plant may be able to read your mind. She probably knew you were going to put her in flower, so she started wothout you. Sounds like my old girlfirend!
Seriously, though, it could be anything. As CSN urged in
Carry On,
Rejoice, rejoice, we have no choice but to carry on
It could be the mix of nutrients. Maybe the daylight cycle was shorter than usual. It's possible her biological clock's ticking. Just speculating, but some plants may have autoflower-like characteristics and be programmed to flower after a certain number of days in veg.
Hopefully, someone will know what is happening. Regardless, it is nothing to worry about.
Before I put my gals into flower, I was experimented with reducing the daylight cycle gradually. Rather than go abruptly from 18/6 to 12/12, I gradually reduced the cycle to 16/8, then 14/10, intending to finally go to 12/12.
Some growers like to do this so that their plants gradually get accustomed to the "change of seasons."
Anyway, when I hit 14/10, I decided the plants were smaller than I wanted, so I switched back to 18/6 for another week or so (can't remember exactly how long).
Theoretically, none of tis should have initiated flowering as there had not been even a single 12 hour period of complete darkness. But my gals knew something was up. As soon as I switched to 12/12, they almost immediately went into flower.
Let me show you what I mean:
It's totally amazing what can happen in five days!
You flushed the plant before flowering.
Come up and get your Merit Badge!
Regarding the leaves curling up: this may have been from a pre-existing imbalance before you flushed them. Unless it looks like it's getting worse, give her a few days to get used to her new environment and see if the condition reverses. If it doesn't or starts getting worse (leaves turning yellow or getting brown spots on them), use the Epsom salts treatment mentioned above.
You might want to do it anyway, just for the hell of it. Some growers use Epsom salts every watering because they have hard water (the minerals in hard water can lock out Magnesium), so one application won't do any harm. Mg is essential to chlorophyl production and that is why the leaf initially turns yellow. An easy way to remember this is:
"If they leaves turn up like they're praying, they're praying for Magnesium!"