I saw you said baking soda and watering but how is regular watering producing white powder on the leaves? Nothing should be getting on the leaves and especially not mid way up the plant. When I say wet I mean a high rh%. Do you know your humidity in the tent?
3 Likes
The water containing the baking soda dried on the leaves. Thus the baking soda dissolved in the water was left behind on the leaves. Sometimes FF big bloom will leave similar spots on leaves. The humidity stays around 47.
3 Likes
Im having trouble visualizing how you water. Youve got some of the white all the way at the top of the plant. You dump your water over the plant? Not being a jackass.
3 Likes
Actually a better question. Have you had this before and it 1000% isnt an issue?
2 Likes
Your humidity is pretty good for the stage of the plant as long as your temps arent too much higher than 75.
2 Likes
So many variables and interactions between each variable in a grow that its tough diagnosing plants from pics. Youve got a lot going on in those pics. I was betting on a high humidity being one cause so Im not sure. Light and heat stress can cause some of your symptoms. Im not familiar with the nutes your using so Im not much help there. The n tox I mentioned isnt horrible looking but something for you to look into.
2 Likes
I agree with this. Too much fertilizer and chasing the PH in soil is an error. If your inputs are the proper PH of 6.5 - 6.7 that is all you need to be concerned with. The roots of the plants will change the PH of the soil in their biome to stimulate the microbes to produce more of something they want. It can be quite dramatic as much as a full point or more. By tryng to correct what is not wrong you have added a ton of stress to your plants. That looks like powdery mildew to me, if it is baking soda you are watering wrong.
6 Likes
Yes I just pour it over the plant.
2 Likes
I see it to a degree in all grows but it’s more pronounced in this grow. I think there’s also some light burn involved due to learning a new light.
2 Likes
This is separate from your yellowing and rust spots issue but I’d stop watering like that. You just need to water the pot. Pouring your water and nutrient mix over the plant comes with all kinds of risks and problems.
3 Likes
I’ll start doing that.
Thanks
4 Likes
Welcome to AFN
I wouldn’t foliar spray anything on flowering cannabis unless you are fighting disease.
Your water pH is way too high. You might be locking out nutrients. In soil try to keep it close to 6.0.
Ditto on the powdery stuff…How’s the humidity and air movement?
Get on top of these right away. You have a week or 3 before harvest.
1 Like
That’s bad
1 Like
I think if you correct said issues, which shouldn’t be too much work at all, your plants will be much happier! You have the tools, and a lot of great people here to help point the way to awesomely epic flowers. Good luck Gromie!
2 Likes
I don’t spray anything on the plant itself. What everyone is calling a white residue is from FF Big Bloom which doesn’t dissolve in water so it dries on some of the leaves. I’ve always understood that the ph for chemical fertilizer should be between 6 & 7 so I strive to keep it somewhere in the middle. Problem I’ve always had is FF nutes will drop the ph below 6 after watering if the ph is already close to 6.
I’ve never had an auto finish in less than 16 weeks or so but perhaps with the new grow light it will finish up sooner.
Heat stays around 77 during the day and humidity stays around 47. My VIVOSUN light has a fan blowing directly on plant and I have and exhaust fan pulling air in through the bottom of tent and out the top.
Thanks for you reply.
2 Likes
Everyone is tripping on the white stuff because they are all wondering how it’s getting on your leaves. Since you’ve said you pour the nutes over the whole plant, that makes sense. Just correct that in the future. Watering the soil is what you want. Watering the whole plant will screw everything up. Also like @Man-O-Green said, don’t worry about adjusting your soils ph, it will fluctuate naturally. Just focus on keeping your nutrient solution in the correct range around 6.0 and you will be fine. And water the soil only, so you don’t end up with weird salty flavored buds and or mold issues. You don’t even really want to spray plants after the first couple few wks of flower.
2 Likes
Through the help of everyone that replied to my post and some research on my own has led me to believe that this is not a growing condition problem or ph. It’s the fact that I was getting the nutes on the plant itself when watering. Causing the discoloration and burning on the leaves. I find it difficult to get water to the middle of the container and not get it on the leaves. So that’s something I have to work on. However I’m not spritzing the plant with pH, balanced plain water to remove the nutrient residue before it dries.
Thanks to everyone for the help!
3 Likes
This is the recommended PH for fertigating the various substrates:
PH for the nutrient mix for soil is 6.4 - 6.7
PH for the nutrient mix for Peat is 6.3 -6.4
PH for the nutrient mix for Coco is 5.8 to 6.2
PH for the nutrient mix for hydro is 5.8 to 6.2
3 Likes
Correction I am now spritzing with pH balanced water to remove the residue from the leaves after watering.
2 Likes
I think you can gently wipe the affected leafs with clean paper towels dampened with pH’d water.
This way you can prevent moisture from accidentally entering the flowers and other nook and crannies, and it’s a faster way to get rid of the residues.
Best of luck with the remainder of your grow
Thanks @Man-O-Green for the pH update. I’ve been in hydro mode for years.
By the way @eruceht pictures are great and it also helps us to help each other if we include more details, like the ones we gradually sussed out.
4 Likes