Posibles problemas

Are you growing with synthetic nutes? If so it could be because your pH is too high. I could be wrong, it’s been awhile since I grew with bottled nutes but I believe 6.2ish pH is where you want to be. If that’s coco I think the pH is a tad bit lower. @Mjcalifornia or @Crackadoo might be better to chime in. I believe they both have more experience with bottled nutes than I do.

Here’s my minimal experience with coco as it’s my first grow! Ph is definitely high for, should be closer to 6. Disclaimer, I use AN PH perfect nutes so don’t test my ph. The foliar spray is good, normally I do every 3-4 days right when the lights go off. The one thing I think you’re having trouble with, which happened to me, is not feeding it early enough. I ran just cal mag for a week or two and then ran half strength for another 2 weeks after and it set me back big time! You should be more aggressive with the nutes

If you haven’t fed yet, do a quarter strength and work your way up until plant says to back off. I just realized that and have pushed to 125% strength and they’ve responded well!

no, I’m using light mix substrate, I only use water with “cal-mag inioc” which is a calcium and magnesium supplement and they told me to put it in all irrigations in the grow, at minimum doses 1ml l,

also this same week I started with growth fertilizer and it’s 1ml cal-mag + 1ml of “topveg” from the topcrow brand, which are organic.

the only addition was a foliar application of plant phytohormones, a few days ago I don’t know for sure if this is possible (I’m experimenting) although it shouldn’t be, if you see the leaves they have some small burns, I can’t diagnose possible problems at first glance, could it be chlorine burns?

I understand that the low growth could be due to the hormones, since they are precisely called youth hormones, what I don’t see as normal are the burns, they shouldn’t be caused by hormones.

if it helps, they are “cytokinins” also known as “cytokinins” or “kinetins”

I gave it 1ml/L of topveg and also 1ml/L of cal-mag, which are the minimum recommended doses, that’s why I find the lack of color strange. This plant is also under hormone treatment, maybe that’s why, but it also has some small burns on the leaves that I have no idea what they are. As soon as I can, I will heed your advice and use growth fertilizer again.

How much light are they getting right now? How many watts, what distance from the plant? How much PPFD?
In the first picture, it looks like the tips of the leaves are slightly turning upwards and have white tips. That would be a sign that they are getting too much light. If you then also spray the leaves for fertilizing while the light is blasting on them, that could have caused the burns.

The pale green, slow growth and brown spots can all be caused by the ph being that high. I generally aim for 6.2 in soil. When it is too high certainly nutrients become less available to the plant and you start getting deficiency symptoms like you are currently seeing regardless of what you are putting in with feeds.

I have a 240w LED light at 25%, it’s about 40 cm away, on 20/4.

How far should the plants be from the lamp?

it is 40cm

Why the 20/4 light schedule? It could be making the dli too high? Just trying to see what variable it may be. If they are autos the 20/4 should be fine, I grow mine 24/0. If it’s a photoperiod they like 18/6 better. Do you have the photone app or a ppfd meter?

That one is auto, there are 5 other photoperiodic ones, they are at 20/4 because the photoperiodic ones are still seedlings. When they have leaves, all will switch to 18/6. I’m just taking advantage of the first few days to give them a bit more light until the photoperiod-dependent ones grow. Yesterday, examining them, I saw the burns on the leaves.

I would raise the lamp 5 - 10 cm further, see if that helps.

If this is Biobizz’s light-mix it isn’t a coco grow . . . more of an organic substrate with a lower EC than say All-mix, more like Happy Frog vs Light Warrior seed starter.

Their coco product is called Coco-mix.

Yes, I never said I used coco, it’s substrate, yes it has coco, but it’s lightmix substrate.

No, you didn’t but others who posted thought it might be. No offense intended.

Second message from him, it’s in the one above.

I just raised the LEDs 15cm, although I don’t feel enough power to burn the leaves; in fact, it seems like little light to me, though I clarify that this is my subjective view, because it’s the first time I’ve cultivated with LEDs; previously, I always used HPS.

If you notice, it looks “sad” with its leaves drooping, wilted.
The spots are not on the new leaves, only on the false leaves; the apex is still pale.

I also attach another photo of the larger photoperiod plant, where the apex also looks perhaps a bit pale, even though it hasn’t even grown leaves yet.

With led’s it’s not the heat that burns it’s the light itself. Led’s run cool so you don’t feel the heat except what comes off the heat sink and driver. The pale leaves just look like new growth looks. It’s a bit paler than hardened off older sections of leaves. The center has more pale that the outer leaf on the meristem. The tips of the leaves are the first parts to be exposed to the light and harden off faster.

I also have a 240 Watt lamp; according to the manufacturer, it would be for a 1.2 m × 1.2 m tent during the growth phase and for a 1 m × 1 m tent during flowering.
My tent is only 0.6 m × 0.6 m. As long as they are small, I place a plastic cup over the plants so that the humidity for the plants is at 80%, and I keep the lamp at a distance of 45 - 50 cm.
I have already noticed that the small plants stand completely normal in the morning and then in the afternoon start to let their leaves droop a bit; I think they have then received the maximum amount of light they can process in