Hmmm, don't think it ready yet??

One of my purple sativa plants has started to show signs of yellowing on the tips of the leaves. Not on all braches tho, just a few. I read somewhere, that's a sign it's ready to harvest in a couple weeks. By my calculations I'm about 7 1/2 weeks into flower and should have another 5 to go at least. So I don't think that's the reason for the tips yellowing.

She's a purple sativa, growing outside in a soil made up of compost, garden dirt, peat moss and chicken manure. I water as needed, usually about a 1/2 gallon a day as it's been warm. Every 7 days or so with ewc tea, and used banana peel tea as a substitute for my ewc tea 2 times ago.

Any ideas for the tips?

I think you have a nutrient issue as this is not a typical look for a plant using up its fan leaves in last couple weeks before harvest. The slight downward claw on some of the leaves suggests it is an overfeeding issue. I'd guess potassium since you did a banana peel tea but that is just a swag on my part so you'll want better opinions. It is not a look I've ever had to deal with so no experience on your particulars. Good luck!

Nowhere close to harvest but you definitely have a nute burn going on there.

My plants rarely use up all the nutes in them and start cannabolizing because I feed them on a reg basis. Sativas can be fussy. My experience with sativas you cant throw a lot of nutes on them when you see problems, you have to ease them into a light feeding and bring it up slowly or you will go from a deficiency to toxicity.

Thanks for the comments. Like I say, all I have given this plant is ewc tea for the last 6 weeks. 4 feedings of the ewc tea and 1 of banana peel tea. The ewc tea was made up of approx. 2 cups ewc, 1/2 cup rehydrated alfalfa pellets, 1 tbsp. unsulphured molasses and 3 gallons rain water. Usually give it 3/4 of a gallon per watering. Guess I will lay off the tea for a bit and just give her rain water and see if it clears up.