What could I have done differently?

Hello,

I am a couple weeks into flowering my second auto, and it definitely does't look as healthy as it should probably be. It's probably too late to do much about it other than to let it finish out and hope for the best, but I'd like to try and figure out what the problems may have been in order to avoid the same mistakes for my next grow. I'm guessing there was some sort of deficiency?

Soil: 5pt coco potting mix w/ perlite
2pt extra perlite
2pt compost (store bought)
1.5 pt worm casting
Lights: 5 x 50W vero29 gen 7 @ 2700k

Ventilation and air flow is good for my tent. No light leaks. Temp stays around 19-24 degrees Celsius (I did see it dip to 17 when the weather first started getting cold). Humidity between 30-60%. Plants were fed plain 6.5ph tap water about once a week.

My goal for the grow was to use amended soil so that I don't need to worry about feeding. The first 5-6 weeks was great. The leaves were a healthy green, lush and grew very fast. I then started noticing the the tips and edges of the leaves yellowing, which eventually spread through the lower leaves during its explosive growth stage. I also realized that my lights were too close, for most of the grow. Unfortunately, I can't do much about it for this grow as I'm limited by my tent.

The top of the plant looks like a bit of light burn, which I can resolve for my next grow, but is it some sort of deficiency I'm looking at at the bottom?

Any other tell tale signs of what may have gone wrong would be much appreciated!

I really wish I had a daily grow journal =/ Definitely going to get one started for my next grow =)

As a side note, this didn't turn out to be an auto. At about 8 weeks, I had to switch the light from 20/4 to 12/2 to start flowering.

I suck at soil.....so.
That looks like combo of nute burn and lockout.
Check your ph.

Good luck

For the future, I would avoid using coco IF you're going to add composts and worm castings. Peat would have served you better and it's a bit more suited for an 'organic' setup. Plants in coco like a pH closer to 5.8, while plants in peat / soil prefer a pH closer to 6.5. Is it possible that you have enough coco in your medium that it's not jiving with your pH...perhaps. Coco is relatively inert and it will take on the pH of whatever you're putting into it...in your case it's your water, your worm castings and your compost. If any of those three components are way off in terms of pH, it's very likely your coco, ie medium, is too.

Yeah that's what my plants tend to look like when they have been deprived of nutes for a week or two and the end of flowering and maybe I did it too soon. So I would agree it's a combination of issues causing the plant not to get the right nutes... As to what I'll leave that to the more experienced, but yeah ph, lockout, burn... all culprits. Personally I might just stick with some Happy Frog or Ocean Forest soil and see how that goes because otherwise that could still be a nice looking harvest.

Also, I don't know about autoflowers, but given that plant shape, I would have topped the cola on the top for a more even canopy, but again, I don't know how autos react to that.. Might help with the tent space. My 2 cents... Good luck.

Choose soil and find a good blend or read up on building a great one to last the grow Or choose coco and feed nutrients so you know what your giving it and your giving it what it needs. One or the other.
Its had too much of lots of things and locked out.

I definitely see nuteburn/light burn on the those upper leaves. The lower leaves are indicating you need to pump up the nutrients. You probably burned the plant in the starting phase. Also the ph as stated could of went out of whack. One thing I have learned about autos, they are very finicky on nutrients. Feed very lightly for the first 1 month and and a week. When all the pistils are coming out and your starting to bud, consider upping the dose. Your leaves will not recover, but you will be fine in yield. Just give her a good feeding, something specifically for bloom. Cheers mate

The smaller plant you have is showing the same signs as the larger.
It looks to me like a potassium deficiency
Sometimes you’ll get something that looks a lot like tip burn with a potassium deficiency, but it goes in further than nutrient burn, and with a potassium deficiency you also see yellowing between the leaf margins.