Nute burn, is she ok?

Hey guys! This is my first grow and I'm trying to assure the optimal/best grow conditions like all of you. I have 3 Super Silver Haze(fem-ILGM) plants under 400w HPS light. my grow room has limited space. 2.5x3x5.2 ft

At first, I had no experience about how to sprout a seed, one of them vegged for 54 days, the others 32 days before flowering. (with a 400w MH light) two of them couldnt make it at my first try because I planted them directly in 5gal air pots.

42 days passed since I flipped them to 12/12. They are compact, bushy plants (considering their Sativa genetics)

Now there is 15-16 inches between the lamp and nearest bud. Is that too high or low? I adjust the light using the back of the hand technique from the beginning. is that wrong?

I tried to make a SCROG and I think screen's too low. but I couldn't make it better because idk if its about my space/ceiling. I had space for them to stretch but maybe I couldn't figure if I should pull the lights up for them to stretch? however, they didn't stretch much and their nodal distance was too short. I was forced to flip them about temp issues since it's getting hot in where I live, I couldn't wait for them to fill the screen.

Air ventilation is fine I guess, in fact I have a ventilation fan bigger than what I need for my grow room.

Medium: Biobizz Allmix
Nutes and additive: Bio-Grow, Bio-Bloom, AN Big Bud, Cal-Mag

I was using 1ml/L like they say in their schedule and I thought I can give them more, and that was WRONG Now I have yellowing and burns on leaf tips and my concern is how this would affect my yield

temps: 65-78F
humidity: %40-%60

I LST'ed em all. Longer-vegged one topped and I defoliated her so much(not in flowering). And I FIM'd the other one(the healthiest and will yield more than others I guess) I cut the lower branches and yellow fan leaves of all. There's yellowing lower leaves on my unhealthy plant and I suppose it might be a N deficiency. I'm here now for getting help from the experienced growers because I didn't want to do anything wrong since they are in an important stage of their life. I also used LightAddict's backbuilding for 6-7 buds and they look denser than the others.

I can flush em but in other thread(a plant deficiency that just look like mine) I read that it could be a straving plant.

btw, by looking at the pictures, how much do you think they'll yield? It's been 42 days since 12/12 and only long-vegged one was showing sex when I flipped them. Which flowering week are they in? 4-5??

How long do you think they have to go before the harvest? will buds get denser after this stage?

I learnt a lot of things from this grow and whatever my yield will be, now I know I won't disappoint. I think I could not grow them to this phase if @calliandra didn't help me. Thank you so much!

Here's full picture of 3 girls.



here's a bud picture when lights on:



All other pictures about nute burn are attached below. I can take more pictures.

Sorry for my English mistakes if I ever did one. Happy grow!

im not sure if that is nute burn tbh m8,, im sure some1 will pop in and help you.. to me it does look like there being underfed but please dont increase the feed until someone more knowlegable stops by... underfeeding is always better than overfeeding... there may be a deficiancy but yet again i couldnt really say for sure...

all in all tho there looking really good appart from the yellowing leaves ,, covered in trics...
im not sure as to how long u got left as i dnt know anything about the strain you have,, do you know anything about the strain like its name perhaps.? if its sativa cross then id expect it to flower for aprox 8-10wks , if it was a full sativa then possible more 10-12wks perhaps... if its indica dominant then id say 8-9wks in flower so in theory you should have 3-4wks left give or take a week...

looking at them id probably say you only have 3-4 wks left untill harvest but im far from an expert m8...

hope someone stops by and points you in the right direction,,,, peace.

hey dmnstrzx -- sheez thanks, glad I could be of help -- they've come quite a ways!

The yellow/dry tips on the leaves: yes, those are nute burn.
Sounds like you already know where they got that from
I don't use nutes myself, but I have read people recommending using only half or even 1/4 of the "normal" amounts.
So yeah, using even more than that did it to them.
If you stop overfeeding, it won't affect your yield.

As for the yellowing leaves in the undergrowth.
Yes it could be the plant pulling nutrients out of those leaves to feed the growth up above - theoretically.
Practically, I don't think so though, since there were even too many nutrients around...?

Anyway, my theory, for what it's worth:
It kind of looks like the canopy at screen level is very thick. So it could be that your plants are dropping those bottom leaves because they are useless for photosynthesis. Also, when you get close to harvest the plants like to empty the nutes stored in the leaves for final bud growth. So maybe what is happening there is a combination of the two.
In any case, just leave them on until they fall off themselves. That way the plant can get the maximum out of them before they die.

As for the scrog, it's definitely not too low, but actually could have been placed even lower to spread out the branches more. However, I really understand that may not have been possible, seeing you mentioned the plants growing short and bushy -- really hard to train when they grow that way!
Actually I had the same situation with my scrog. My theory is that I had my lights too close during veg (I was scared of them growing too big, haha!)

The hand technique is fine for getting the lights to a good height in flower too btw

As to yield -- noooo idea, I'm terrible at guessing that
But yeah, you have another 3 weeks going there, maybe more, because the pistils are almost all still juicy & white. You can start thinking of harvest when about half of them dry up (and turn orange/red/brown). Thats the time to get a magnifying glass/ mini-microscope and check on the trichomes!

As for counting flowering phase: some people count from switch (including the stretch in the flower phase), others count from when they really start blooming (which is usually around 2 weeks after switching to 12/12). Personally I count from showing flowers.
I do suspect that seed banks count the flower time from showing of flower too. When people count from the flip - and then get impatient their plants aren't done in the time they're "supposed to" - it's usually exactly those 2 weeks' stretch that they still have to wait.

Hope that helps!