My plants' top leaves are yellowing and dying. It started in week 4 of flower. I did a mild flush on week 5 with pH 6.9 water but it just made it worse. I'm still new to growing but I've been doing everything by the book. I saved up for a year for this grow..please help me save them. Lights: Advanced LED 300w Medium: FFOF with Dolomite Lime Runoff pH: From 6.7 to ~7 Nutrients: Advanced Nutrients Sensi Bloom A/B at 1/4 strength every watering. (Stopped nutes 2 weeks ago in case it's a nute burn.) Veg time: 4 weeks Containers: 1 gallon smartpots (I don't think they're rootbound as there's an auto showing the same problem) The problem: Leaves yellowing and becoming crispy. Started with only the upper big leaves. Now it has spread to all upper leaves, even the tiny fan leaves around the buds. Bottom leaves are not affected yet. Week 5 (a few days after the mild flush) Week 6 (no nutes for 2 weeks) What could be the problem? I have an auto which is displaying the same problem, so I don't think they're rootbound. My only guess is that the FFOF soil is the culprit as it tends to be too hot.
Im going through the same thing right now. Best of luck getting it taken care of. What are temps in your tent? Mine are between 77 and 83. I am using fox farms happy frog with the fox farm trio of nutrients. I just fed her 2 days ago so I am hoping its not nutrients. I am really lost at the momment.
fyi: https://www.icmag.com/gallery/data/500/1134nl-Phosphorous2.jpg I got this from: The Complete guide to Sick Plants,pH, and Pest troubles! - International Cannagraphic Magazine Forums Solution to fixing a Phosphorus deficiency Some deficiency during flowering is normal, but too much shouldn't be tolerated. Any chemical or organic fertilizers that have Phosphorus in them will fix a Phosphorus deficiency. If you have a phosphorus deficiency you should use any N-P-K ratio that is over 5.Again Peters all purpose 20-20-20 is a good mix. Miracle grow Tomato plant food, Miracle grow All purpose plant food (Only mixing at ½ strength when using chemical nutrients, or it will cause nutrient burn!) Other forms of phosphorus supplements are: Bone meal, which is gradual absorption, I suggest making it into a tea for faster use, where bone/blood meal is slow acting, but when made into a tea it works quicker! Fruit eating bat guano, which is fast absorption, Worm castings, which is gradual absorption, Fish meal, which is medium absorption, Soft Rock Phosphate, which is medium absorption, Jamaican or Indonesian Guano, which is fast absorption. Crabshell, which is slow absorption. Tiger Bloom , which is fast absorption. Here is a list of things to help fix a Phosphrus Deficiency. Chemical Advanced nutrients Bloom (0-5-4) Vita Bloom (0-7-5) BC Bloom (1.1-4.4-7) GH Flora Bloom (0-5-4) GH Maxi Bloom (5-15-14) GH Floranova Bloom (4-8-7) Dyna-Gro Bloom (3-12-6) Fox Farm Tiger Bloom (2-8-4) Awsome Blossums Organic Dr. Hornby's Iguana Juice Bloom (4-3-6) Advanced Nutrients Mother Earth Bloom (.5-1.5-2) Fox Farm Big Bloom (.01-.3-.7) Earth Juice Bloom (0-3-1) Pure Blend Bloom (2.5-2-5) Pure Blend Pro Bloom (2.5-2-5) Buddswell (0-7-0) Sea Island Jamaican Bat Guano (1-10-0) Indonesian Bat Guano (0-13-0) Rainbow Mix Bloom (1-9-2) Earth Juice Bloom (0-3-1) BIO BLOOM (2-6-3.5) AGE OLD BLOOM (5-10-5) ALASKA MORBLOOM (0-10-10) METANATURALS ORGANIC BLOOM (1-5-5) Any of these will cure your phosphorus deficiency. Affected leaves will not show recovery but new growth will appear normal. Now if you added to much chemical ferts and or organics,( which is hard to burn your plants when using organics) You need to Flush the soil with plain water. You need to use 2 times as much water as the size of the pot, for example: If you have a 5 gallon pot and need to flush it, you need to use 10 gallons of water to rinse out the soil good enough to get rid of excessive nutrients. Note: Blood Meal, Dried Blood, Guanos, Kelp Meal, Cotton Seed Meal, Peat Moss, Sulfur and fish meal are all acidic and can bring your ph down, so if you add these please monitor your ph when using those. Note: Bone Meal, Rock Phosphate, Wood Ashes pretty much all ashes, Shellfish Compost and Crab Meal are all alkaline and can make your ph go up, so if you add any of these please monitor your ph. Picture 1 is a Phosphorus deficiency during vegetative growth. Picture 2 is what a phosphorus deficiency looks like in flowering. Picture 3 shows phosphorus being locked out due to cold temps for the seedling
Put your ph at 6-6.5. Now is the time to start talking away nitrogen and put in More phosphorus & potassium.
6.3 - 6.9 my bad lol bongin so I looked at my sheet and saw that so had to tell you. Wouldn't feel right giving bad info