HELP! Can't Identify Issue With Sick Plant

[pandaren11]

Hello! I’m currently growing three dutch passion white widow plants inside a 2x2 tent under a 120w led with a good exhaust and oscillating fan.

They’re in 3gal pots filled with 80% peat moss, 20% vermiculate + NPK traces, EC = 0,7. On top of that, I've added the following amendments: 10% worm castings and 18 grams of cockroach castings, 18 grams of mealworm castings and 18 grams of bokashi.

I’m using a local organic fertiliser which has always worked out perfectly from veg to flower in all of my runs.

Symptoms are limited to top/new growth: leaves discolouring from the tips, rust/brown spots in a few leaves, leaves canoeing/tacoing, slow growth.

I’m thinking this could be a sign of deficiency, but I’ve raised the fertiliser dose and it hasn’t really stopped. I’m pretty sure the watering schedule is fine since I’m relatively experienced and this isn’t something I’ve got wrong in a long time.

Most people seem to think it's a magnesium deficiency, but I thought mg deficiencies were supposed to start from older leaves, progressing upwards as it gets worse. This issue has started from the canopy and is, apparently, progressing down.

I've raised the light a bit and the plant is praying again, but leaves seem to be discolouring still.

That aside everything looks good, so I’m stumped as for what to do to rectify this issue. Any help will be GREATLY appreciated! Thank you!

[JeffInCanada]

Hi pandaren11 I'll take a try at this one...you provided a lot of good information. I'd say that the light is too close. You mentioned tacoing/ canoeing leaves and that is a sign of heat and light stress. Also, you mentioned praying leaves. If you mean that the leaves are pointing up at about a 45 degree angle, this is actually a sign that the leaves are getting too much light. I say, try raising the lights up a chunk.

Good luck!

[Mr.furley]

Agreed

[ZigZag]

I’ll second that. Have had same issues before. Those damaged leaves won’t heal but the new growth should come in fine. I’d raise them a few feet ASAP for a few days and then start bringing them down until you’re getting about 600-800 ppfd at about 18-28”, some strains don’t deal well with more light than that. Put your fans low so they blow the heat from the lights up away from the plants. Hope that helps.

[3Berries]

More K and Ca is my guess. I have this problem in my grows. The nutes I use were way low on K compared to others. So my next grow when starting into stretch I'll be adding some K along with the Mg and flower nutes.

[Mr.furley]

No mention of pH and pH practices, peat is acidic and your mixes sounds Hot to me, raise your light as Jeff said until you can give some more details about temp, Rh, pH.....

[pandaren11]

Temps are oscillating between 24ºC - 26ºC / 76F - 78F, RH stays between 65% - 73%. Will report back tomorrow with a medium pH reading.

[ZigZag]

I’ve had my PH rise a point or more by adding too many casings, worm and others, maybe flush them really well as well as raising the lights. If your medium is too hot all you can do is flush them with plain water, I use PH 6. Flush until the drained water is between 5.5-6.5.