Hey guys, first time grower here. Growing a sativa autoflower and im at about 5 weeks into flowering (10 weeks since germ) growing in FFOF soil under LED, giving bloom nutes and cal mag once a week (not on same day), and keeping PH in check (runoff measuring at 6.3 when watering with 6.5 tap water) lights on 24/7, temperature is an unwavering 78-80F, humidity controlled at a constant 50%. light is the recommended manufacturer distance away from the plants, and if anything may be underpowered (450W LED advertised), so i doubt its light burn of any sort. definitely not overwatering, i have good drainage and wait until plants are dry at least an inch deep. I seem to be following everything to a tee and the data all looks correct, but my plants still seem to be suffering from something, there are various signs here: clawing (despite not feeding much N at all ever...they clawed before i ever even gave nutes because i was told to wait at least 45 days when using FFOF), a lot of yellowing leaves (is this normal this far into flowering?), 'Burnt purple' tips on fan and sugar leaves, slow growth. im hoping somebody can have some insight for me. thanks!
Early nute burn either miss 2-3 feeds or flush with 3 times the pot volume with air temp ph'ed water allow to drain overnight to continue in the morning no nute for 10 days good luck
It's most likely a phosphorus deficiency. What are you using for flower nutes, how much once a week? You might need to feed Bloom nutes more like twice a week. I think your medium is holding water too long. On next grow, add about 30 to 40% extra large perlite for better drainage so you can water more often and provide nutes without overwatering.
Not a solid medium grower, but do have experience with 24-0 lights and autos. Manufacturer light distances are too close when running lights 24-0. I'd say light stress is causing symptoms that will fool you. I've had to go from 20-4 to 18-6 lights because plants were getting light stress, which just makes plants unhealthy and prone to unpredictable ailments. I'd give them a few days of 18-6 lights and see how they respond. Chasing non-CalMag deficiencies is a fool's errand.
Looks similar to what I just dealt with had been slowing overdosing on bloom nutes which appeared to show deficiencies which I believe we're nute lockout...can't recommend flushing enough..did a flush and corrected final solution and 2 days later they look good again...this is a good guide from the cannabis I also topdressed with dolomite lime to help keep my pH in the zone encyclooedia Sent from my TA-1033 using Tapatalk
wow guys, thanks for the insightful replies, will make a few adjustments and see how it goes these next few days. Thats an interesting point regarding my lights bk. It did previously go through my mind that maybe 24 hours is too much at manufacturer distance. @Budhound -- im using FF tiger bloom, about 1/2 the recommended dose once a week im on the fourth week. I dont understand how it could be missing phosphorous unless its a lockout of some kind but PH is in the 6's... A lot of the lower leaves have been yellowing, which I find a few explanations for online ranging from normal to not.
