Hi mate, I see some nutrient burn on the tips It could likely be due to high VPD levels, what happens is as VPD increases the transpiration rates increase so the plant will uptake higher levels of water from the media to help cool themselves down, the problem is along with the water they will pull in additional nutrients & they will build up within the leaf tissue and in excess will cause the notorious “Tip burn”. Aslong as your providing the correct EC levels and maintaining the correct VPD & PPFD levels the tip should clear up.
Alongside the VPD it’s possible you have too high of a media EC which is a result of either too high levels of nutrients, allowing too heavy of a dry-backs between irrigations or not providing enough runoff with each feed, all of which will cause EC levels throughout the media to “stack” and accumulate causing the root zone to become acidic. The build up of nutrition will cause your PH to swing into the lower ranges, leading to nutrient deficiency and toxicities.
From what i can see the plants look relatively healthy overall i can see some purpling throughout the stems which is usually a sign of under feeding or some kind of nutrient deficiency likely P of magnesium. It’s likely you are providing the right amounts of nutrition so this could just be a case of Nutrient lockout at the root zone & what your seeing on the leaves right now is the start of a potassium deficiency the classic signs burnt looking tips with the outer leaf margin yellowing. Tends to arise mid flower where the plants are eating high levels of potassium.
Assuming your around the week 5 stage this is where P,K demands increase & because they can’t access these nutrients from the acidic media they will use up what’s in there leaf stores. I would personally reset the media PH & EC levels by flushing the plants with a 2.0/2.2EC feed of your Base & Bloom nutrients at a PH of 6.3-6.5 until your runoff numbers are back in range (5.8-6.2) i like around 6.2 PH during the middle of flower, you will likely need to use a good few litres of solution to get them back into correct range. Within 24-48 hours you should see improvement and the issue resolved.
Also what sort of PPFD levels are your currently providing as it could also be a touch of light stress starting alongside the K issue, 800-900 PPFD is usually around the maximum most strains can handle without additional co2 before showing signs of Light Stress or other issues so I would just double check those levels to begin with and then move onto the flush to correct the lockout issue.
I hope some of this can help you get back on track, you might be fully aware of the above but it’s always good to go over some the fundamentals, any additional information such as your Day/Night temperatures, RH levels etc would also help a ton in further diagnosing the causes but based off just that image it’s what i can gather🙏🏼
So to give more info it is about to be the start of week 4 I’m running organicly I actually just top dress last week with Gaia green 284 and 444 along with build a soil worm castings I’m running a spider farmer sf 1000. And as far as ppfd and things like that I’m just a simple home grower don’t have the equipment to test that stuff but. The light is on 100% possibly part of my issue and I hope that this top dressing kicks in soon. Being that I’m running organicly I try to keep up with my waterings without getting to dry I tend to water a day after the plants stop praying or perking. Thank you for the insight.
Sounds good my man🙏🏼 If you haven’t got a light meter download an app called Photone and pay the $6 for the LED option this will give you your PPFD readings & it’s super accurate been tired and tested it almost as accurate as the those apogee meters.
If you have a PPM pen just check what sort of levels your getting it could possibly be a case of low PPMs that’s causing your issue and the plants just may need additional food, yeah the top dresses are slow release so if you’ve added enough on the last feed hopefully you should see improvements over the next 7 days after the microbes break down the food🙏🏼
@Reeceg Welcome to the forum. It looks like you have a great grow going on. I get those brown tips on most grows.
What cultivar are you rocking there?