I have a question, it's the eleventh week, I ...

If by vitamin you mean fertilizer for the plant or plant feed, they need food until about a week or two from when you plan on harvesting. If this is liquid nutrients that's easy to do, just use water no vitamins/fertlizer/plant food If you use dry amendments you can stop 3-4 weeks out from scheduled harvest date. The plants will start to fade before its ready and it does not mean it needs more its just a natural cycle of death for the plant. PS. Autoflower do not like as much feed as photoperiods so you can get away with as much as 1/2 the amount of feed. Best Of Luck!

omg... this is an autoflower and believe me when I tell you that you do NOT have 6 more weeks of flower! LOL! Your plant will be dead on the ground by that time and the THC in the trichs will have degraded to nothing... But seriously, you need to keep feeding them up until about the last week - whenever that is. When the pistils start to turn brown is when you want to start taking a look at the trichomes to see if they're getting ready (or ARE ready) for harvest. If you don't have one, get yourself a microscope or a jewelers loupe - even taking a zoomed-in photo and then zooming in on it will help you see the trichs. You're going to want to see them all milky with some of them being amber. When you FIRST start to see the amber is the best time to stop feeding them and giving them plain water since you'll have just about one, maybe two weeks left to harvest. But I see a couple of things in your diary you need to pay attention to quickly - first and foremost is the pH... it's much too high for cannabis... that needs to come down so it's between 6.0 and 6.5... and pH everything you give her - water & nutes. Secondly, you should probably start her on a PK boost as plants at this stage are needing a lot more potassium and phosphorus than is normally found in bloom nutes... this will make the buds larger and denser. Good luck the rest of the way!

Your plants still need around 6 weeks flowering time. And you give nutritions till the last week. The last week you only give water with the right pH.