when to start night temp control to get purple colour on plant/bud

dropping the temperatures will induce a color change by killing chlorophyll in the plant, the most efficient engine turning light into something usable. if you are asking questions about this, you might consider not doing it.

@TeesTrees disregard the previous answer as other factors can turn plants purple than genetics alone potassium deficiencies can do it as can very cold temps which it seems is the way you are thinking of inducing colours into your plant. However not all plants will exhibit purpling in lower temps so its a bit of a hit and miss experiment on your behalf in all honesty I would concentrate on achieving the best yield you can get from the plants rather than attempting a colour change .

High bro, As i mentioned in your earlier question. Genetics make your plant go purple, please look at my Blue Hash diarie. I did not do anything to make her purple it is genetics. When you want a purple plant or red buds you need to search for the right genetics. If you are interested in this you can search for the strain, Red Hot Cookies form Sweet Seeds or Purple Bud from White Label (I grew this one myself and it is a delicious berry tasting Indica strain). Happy Growing! 😋

I would not focus on trying to make it go purple for a few reasons. number 1 is its a massive waste of energy to install ac just to make it turn colours. number 2 is that only the fan leaves and some tips of the buds will turn purple, does not penetrate into the nuggets. number 3, its only a week old. and this is something that gets done in the last few weeks of the plant, if its getting cold every night from a sprout to harvest it will have stunted growth as the purpleing is caused by chlorophyll breakdown and that's need to grow your plants nice and big. As for an organic option of how to increase purple there is not a lot available for that. there is a product on the market called purpranter or something like it, it is said to make natural purple strains more purple but I don't trust it works. It would be a much better investment into your time and pocketbook to just get a strain that is naturally purple/red. this was my Dinamed CBD Kush plant that is very purple, the stain is by Dinafem but no longer available. I did not add in anything or do anything different to make it that purple. It was not exposed to low temps its just how it grows. growdiaries.com/diaries/129779-grow-journal-by-m0use Good Luck! ***disclaimer, multiple people are answering all questions as there is a contest called GOTM, when a user is selected as the answer they get a point. Please see the contest page for information regarding the details: growdiaries.com/giveaways/GotM-August-2022 Please note, when you reply to anything on the questions part of Growdiaries website, no one will be notified of this. Not even if you use a "@" tag in their name. Best to reach out to them in DM using your inbox, it can be found in the bottom right hand corner of the site. It's the small paper airplane button, it will be highlighted green if you have new messages***

You don't have to do this really get the tent fans x 2 filters and twin fan controller first before anything else learn the basics and then u can play around with making the plants purple and I'd try to get photos instead of autos I never get big yealds of autos max 1oz a plants and that's with no stunted growth cos your autos going to flower soon and there's not much you can do to stop it im afraid