Mag deficiency, or overwatered coco?

[Olderfart]

I am not sure it is a symptom? the coloration crosses the veins which is unusual in a magnesium lock out. It may be a little bit of variegation which is genetic. The plant is young and they often show strange growth early. That said are you fertigating properly? Start no sooner than two hours prior to lights on and stop fertigating two hours prior to lights out. Fertigate to a minimum of 20% run off to waste every day you fertigate. If you are doing recirculating recirculate the volume of your reservoir each day and watch the PPM when it drops by 100 - 150 PPM change the reservoir. PH to 6.8 as often as you can. The ok range is 5.5 to 6.1

6.8 in coco?? Methinks 5.8 would be better. a typo perhaps.

 

[Olderfart]

No worries, they were fertigated 2 times a day.

I started this grow by pre-watering the solocups, then letting the pre-germinated seeds sprout. They weren't watered for around 2-3 days after planting, and then got 1 daily fertigation for 3-4 days, and then 2 fertigations per day til runoff, always raising EC/PPM until I hit my max schedule.

I only let them dry out for a few days (2-3) after transplant to let them grab onto the substrate, after which I go back to fertigating as usual. The 24/0 is just because they're autos. My current other Autoflower enjoys 24/0 a lot, taking up almost 1/4 of the 4x4 tent while in early early preflower, no stretch yet:

View attachment 1690103

As mentioned above, they do get treated the way you prefer, even though some criticized me to hell for watering plants in coco twice a day, I kept it that way. The reason I'm coming here is because some show symptoms I've never seen before, and I wanted to know if anyone has an idea as to what's going on there, especially because it's only on two of the same strain.

Is there no one who has seen a symptom like I've shown above in the thread? I can't be the only one, I ain't that special

FWIW, it looks more like variegation than nutes to me, but I never get that high in EC/PPM. With top irrigated coco, I rarely get higher than 1000-1200EC or so before the tip burn starts.

As to watering coco twice a day, in solos, my plants get fertigated twice a day from the moment the tailed seeds goes into the coco. In larger pots they still get nutes a couple times a day, but they get it for longer before increasing fertigation frequency. In solos, the girls are getting 6 fertigations per day by the time they are a couple weeks old. In big pots, they get six per day somewhat later, I can't recall, and doubt that it makes much difference in coco. Regardless of pot size, daily fertigations are large enough to produce about 10-20% runoff over the day. Bottom line with coco is that I keep it wet with balanced nutes 100% of the time. I never let it dry out. With top irrigation, if the top surface looks dry, IMO you have let it go too long.

I am no expert at this, but my impression is that at least in ventilated or fabric pots and coco mixed with 30% or more perlite, it is impossible to overwater coco. Doing so just wastes nutes, it is extremely unlikely to cause problems for plants.

Your plants look great by the way.