Purple Diesel and Fruity Pebbles help needed please

Hi Guys,
I am currently a month into my first grow and have a few issues.
I have used this forum pretty much every day to search for symptoms and advice and so far it has been extremely useful but right now I cant seem to pin point my exact issues.
Im not entirely sure how to set out my information so I will try to make it as clear as possible, if there is a set way then please inform me and I will edit this post.

Strains: Purple Diesel, Fruity Pebbles and unknown
Grow Medium: Canna Coco Professional Plus and Perlite (80% / 20%)
Lighting: 2x Eurolux 600w HPS (I have another for flower)
Temp Lights on: 25c/77f
Fans: 8'' RVK out / 6'' RVK in
Nuits: Canna Coco A and B, Canna Rhizotonic
Tent Size: 1x2m x 2.4m
Feeding Schedule: Water, Water, Feed...I use Rhizotonic every 2nd/3rd Feed
PH: 6.2-6.7
Distance from lights: 11''
Time Schedule: 18/6..12pm til 6am off
Current Height of tallest plant: 8''
Avg Number of nodes per plant: 4-6

I have grown from seed and they are currently 27 days from popping, I have transplanted twice so far and intend on transplanting 1 more time just before flower.
The problem that I have is that some of my leaves seem to be drooping and also yellowing, at first I though they were under or over watered.
I have taken advice from here by reading threads and only water or feed once the top 2'' look/feel dry, this is currently about every 2-3 days.


I have included these pictures to help diagnose my issues.

The questions I would like answering please are:

What is wrong with the little plant that looks rather sad and unwell and how do I fix it?
How can I make my plants look happier and healthier by stopping the droop and yellowing?
Do these look a little short for their age and could they have been stunted by transplanting twice so young?

Any advice or other tips would be hugely appreciated and if I have forgotten any info I apologise and will add any info if needed

Thank you in advance.

What is wrong with the little plant that looks rather sad and unwell and how do I fix it? .............................Note the little perlite is a clue, suspect compaction and wet roots?

How can I make my plants look happier and healthier by stopping the droop and yellowing? .........................Potup (transplant to a bigger and final pot) they are speaking to you ...you ain't listening!

Do these look a little short for their age and could they have been stunted by transplanting twice so young? ..........Possible, I potup as you do, its an opportunity to check the root condition, should be thick white stubby roots in veg

Don't do it with Autos as the time delay 24 hours plus is too much of a hassle with autos, but Photos with an average life of 4-6 months is good, listen to your plants is all...and you too will kick yourself in time to come, from the word go ....see them as pets like fish or birds even as a cat, to get your mind in the zone ...lol yellowing leave and droopy leaves can well mean time to potup.

Any advice or other tips would be hugely appriciated and if I have forgotten I apologies, and will add any info if needed ....Relax you are doing well ...!

Thanks for the quick reply
I only repotted 7 days ago so wasnt sure whether to do it again yet, I will do it as soon as they dry out abit as i only fed them today and keep you updated.
When repotting can I shake off the the soil to reduce compaction in the next pot? Would that be advisable to let them ''breathe'' or should I just pop them straight into the new pot and coco as they are?

Also as a side note...Some of pots look like the perlite is different in each pot..It is correct and uniform in all pots but due to some stretching I added a little bit more coco into the stretched ones to keep the heights the same when they were younger.