A few yellowing leaves here and there is 100% normal for a flowering specimen. When they flower, you are replicating their natural clock where its time to shed leaves, make fruit for the winter, just like when fall comes and the colors of the leaves change and die. A few stragglers here and there is nothing to be worried about.
Also, I have used the BT powder version before, I stopped using it because it wasn't as effective as the liquid treatments. Your also gonna have to seriously consider washing your buds really good at harvest time because the dust is composed of silicates and you do NOT want to be inhaling residual dust particles.
Check out Bud Washing, if you haven't already.
Looking great overall
As a general rule, if you feed organics or grow completely organically, you simply do not need to flush.
If you've been feeding synthetic nutrients that don't contain natural and organic ingredients (such as fast acting salt types), then you would need to flush for 1-2 weeks prior to harvest
But at this point, if I were you I wouldn't be worrying about flushing right now or at all, since this appears to be an organic grow. You still have approximately 4 more weeks of bud development. Right now, you should only water this plant when absolutely needed, like when the most of the entire pot drys out and its dry as a bone, then water.
Don't over water as this can be a crucial rookie mistake that could lead to bud rot, especially in an excessively humid environment. You could certainly get a couple of phosphorous dominant feeds in to help bud development as well. You no longer want to be adding a nitrogen dominant fertilizer.
Flushing can be the kiss of death for a plant, if you live in a humid environment and you're overwating, than budrot is more likely to occur. So that's why its so important to stick to the dry/wet cycles for watering.
It may not even be worth flushing due to the potential for bud rot, especially if your on an organic diet
this is awesome information I had no clue that flushing was unneeded for organic grows and even more so didn't know that it could cause bud rot, you probably have just saved me from an epic fail as my outdoor climate is extremely humid most days. I have been sticking to the dry wet cycle since veg sometimes a little too dry I think I try to wait till the very first signs of under watering with our extreme temperatures this still leaves me watering about twice a week. You mentioned using a nutrient higher in phosphorous, do you have any suggestions for something organic that will also work well with the general organics line? Also I'm currently doing an 11/13 light cycle do you think that switching to maybe 10/14 would aid in bud development as well? I don't mean to overwhelm you with questions but I've seen your posts on many other journals and have been secretly hoping you'd stop by mine some day as you seem incredibly knowledgeable. So again I thank you for your time and help.
Thank you for the kind words, I'm glad to help. As far as the nutrients go, make sure you look on the bottle to read the composition of what you're feeding. In general, you need a NPK ratio that is similar to something like 4-5-4 (kinda too much N in that ratio), or 4-10-7. So check on the bottles, you want something like 4-10-7, all I can really tell you is what I use which is Dr. Earth "Flower Girl" that I brew teas with. However, a prime source for high P for organic growers is "Bat guano", which I use the solution grade by Earth Juice (you might consider looking into the high P bat guano).
Ideally, when a plant is ready to harvest, you want all the nitrogen to fade away and ideally the plant should turn completely yellow because its using up all stored nutrients. You don't want the plant to have excess nutrients at harvest, otherwise it could affect flavors.
About the lighting, yeah, a little bit less light will help the plant make the bud, I currently flower my gals on appx a 12/12 cycle. If I were you I'd hope for dry conditions and just keep inspecting.
To be honest, you may not even need to add nutrients, it's just an ideal sort of thing if your starting soil is real good. There is a lot of nutrients in the organic matter in the pot, which is being broken down each time you water. Just keep going with the flow, you're doing great for a first time grower.
