Yellowing edges/Stunted growth? (Pics)

Looks like my pictures didn't work in my last thread, here's an updated one.

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The plants in question are being grown indoors, are watered every 3 hours for 15 minutes in Rockwool cubes. They are in early vegetative growth and sit about 2' away from a 1000w MH.

This is six days into my first grow.


I think I have a good idea of what's going on but I'd really appreciate an experts opinion. When I took my pH the other day, it was at a staggering 7.8 and since then I've lowered it to 5.5 with 20ish drops of phosphoric acid.

My assumption is that because the pH was so high I was getting fairly extreme nutrient lockout and causing the yellowing/burnt spots and stunted growth (they have been roughly the same size since I bought them).

I'm following the Advanced Nutrients 100% organic calculator (Iguana Juice Grow, F1, Piranha, Tarantula, Sensizym) toned down by 20% as recommended by several posters. I definitely don't think it's nutrient burn as my PPM is ~200 as of today.

At this point I'm assuming they're a little shocked from the super high pH of my reservoir, but will be healthier in a day or two and resume normal growth.

I feel a little lost though, so any suggestions are greatly appreciated.

Also, the picture of the last plant with the severely burned lower leaf is not indicative of general health. That leaf was drooping into the nutrient solution for a day or two where I couldn't see it.

looks like Nitrogen deficiency. try using half of what the advanced reccomends, then working ur way up. ur right about the pH not letting it uptake the N. it just looks like plants do when they start a flush. whatever u do, don't overfert to try to compensate, just give it some time with the adequate pH, and if it gets worse, post more pics because a lot of deficiencies can look similar in the beginning stages.

oh and make SURE those cubes are not too wet!!! i have lost tons of clones that way. if u can squeeze water out of them, htey are too moist.

Yeah, that ph was more than likely the problem.
Plants look good! Keep up the grow