When to stop giving nutrients..

I was wondering...I got some random seeds that actually turned out really good and I think Im getting close to harvest. Im in 6 week of flowering and theyre covered with crystals...Leaves are changing colors and dropping. So is it now Im supposed to start giving them only water for two weeks? Or flush first??

flush first

"Flushing" is giving them just plain water!

Stop a week before you harvest and water with regular ph'd water.