a lot of people like to switch to flowering nutes around a week or so before putting plants on 12/12. I usually do it at the same time. I know someone who waited to start using flowering nutes until a week or so after switching to 12/12 and he said his plants still started flowering just as early as normal. any of these options will work, but i would definately put them on flowering nutes before 12/12 or at the same time. I wouldn't wait to do it afterward. here's what i always do. i transplant into bigger pots that will last throughout flowering the day before switching to 12/12. i moisten the new medium with a light solution of flowering nutes. If you are using fertilized soil or don't need to transplant before flowering however, this is probably usless to you. watch for nitrogen deficiencies early in flowering. i get this sometimes after switching. you shouldn't have nitrogen deficiencies until late in flowering.

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