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Skill_Murray started grow question 4 years ago
Can anyone help sort out the issue I'm seeing on the lower leaves? I think I'm either between nutrient burn or potassium deficiency? I did up the nutrients a bit this week when I saw yellowing, but also have had high runoff pH the whole grow. Though haven't seen any other issues.
First Grow
17 weeks
First Grow Skill_Murray
Blue Dream CBD
40 comments · 3 years ago
Week 13
Leaves. Other
Removed answered grow question 4 years ago
First of all, without clear pictures of the affected leaves I can't be sure of what exactly it is.
A deficiency at the end of the stretch, beginning stages of bud production is normal, if it shows on the lower leaves with dark / metallic blue spots and withering it is phosphorous deficiency, sometimes it also comes with red / purple petioles (stems attached to leaves); chlorosis (yellowing) starting at the tip and edges of the lower leaves with rust spots close to the edge of the leaves if it is potassium deficiency. If it looks like homogeneous yellowing with no spots, it's nitrogen deficiency.
During stretch, some nitrogen deficiency is quite normal, since the plant explode with growth; P and or K deficiency after stretch is normal too, it just means that the feeding needs to be stronger or done more often). Your bloom nute is 2-4-4, I would up the dose or frequency, what is the EC / PPM of your feedings? At this stage I usually feed 1.3 EC / 650 PPM.
As for soil run off PPM's, don't pay that much attention to it, it's just a way to see how exhausted your soil is and how much nutes your plant is taking related to your feeding. Mine starts at 10.000 PPM (yes 10 thousand PPM) and when it's at 5.500 PPM my plants show definitive signs of deficiencies and it is when I have to start feeding; at the end of the flowering stage, even with feedings, my run off PPM is between 1.000 PPM and 3.000 PPM, as long as you run off PPM is not increasing you are good to go.
Stick answered grow question 4 years ago
Hi @Skill_Murray! On the first sight this looks like a Potassium deficiency. But looking at the amount of nutrients you gave her for the last weeks I think giving more nutrients now will not help. My guess is that you created a nutrients lockout / salt build-up, her roots can't absorb nutrients anymore (especially Potassium). As an emergency move I would flush the soil with plain pH'd water for a few days and test the runoff pH level. If she looks better, give her a good meal with appropriate pH/EC levels and see how it goes. I'll be around, keep us up-to-date and happy growing!
Kindbudz answered grow question 4 years ago
Looks like a classic potassuim deficiency. What is your TDS/EC readings? Also if you are adding nutes and water at a ph of 6 that is a bit on the lower side for soil. I would recommend keeping it at around 6.5. Now if you are keeping it at a 6 because you are experiencing runnoff at a higher ph double check it by using a clean glass or container to check the runnoff as the runnoff tray underneath the pots can catch and contain dirt, nutrients and debris that can affect your ph readings. Hope this helps and good luck on your grow!