Stunned or not ?

Purple stam doesn't rly tell u much many strains do this from alone and as other wrote below likely over watering at start and the pot size I also start my autos in a smaller put in moment they reach button ( pot with holes ), I immediately report never had issues with triggering flower like that. You won't get it stunt like that.

'they' say to use a final pot for autos, but all that does is make it incredibly difficult to water with no benefit. In 300-400 'tranplants' (this is better described as 'potting up'), i've yet to see one plant get stunted from such a process. It is not stressful to gently place a plant into a larger media and cover it up with more media, lol. "Transplants" outside are a different animal and that's where the reputation comes from... outside you cause significant damage to roots when you transplant and most certainly stress the shit out of the plant doing so. This is not a concern for potted plants if you don't destroy the rootball while doing it... don't get handsy like a catholic priest. If 15 days is accurate, this is definitely small. Could be one of many reasons.. so i'm not going to sit here and guess, but i'll explain a better process to follow. coco coir is soilles, so follow soilless growing methods. Check out cocoforcannabis.com - guides and articles... avoid the forums. Avoid forums everywhere, lol. Half the shit stated on marijuana sites demands skepticism and 80% of user-submitted stuff, lol, including these grow questions on GD. Their guides and articles are the best info i've seen out there that limits incusion of nonsense bro-science stuff. irrigation - always fertilize, always get 10% runoff. 1) fully saturate with 10% runoff 2) wait for appropriate dryback and repeat. That's it. Don't over think irrigation. A well-balanced diet for soilless/hydro is all you need. 600-700ppm is never too much, overall, but individual ratios need to be dialed in based on observing plant symptoms. JAcks 321 is an excellnt forumal to mimic even if you don't use that product. megacrop, cropsalt, kosher-something, souther ag, masterblend all use a similar soilless/hydro formula, because it works well.. it is not a coincidence that they all have a similar formula. seedlings can be a diffferent context. Feeding at 1/2 strenght isn't a bad idea to start. Go easy with light until it starts to stretch, then amp up as needed... You may want to irrigate a bit sooner with a seedling than you would with a more mature plant, but you still don't want to over-do it. Always fully saturate and get 10% run off in coco. This act alone is never the problem. Doing it too soon after is a problem. Feel the weight of the pot after you water.. weight loss is probably a better trigger than feeling the top drying. With coco and a mature plant, when the top starts to change color from drying, that's usually a good point to re-irrigate. You can push this a bit, but while you learn i'd stick to what is orthodox until you have some good grows and a proper expectation to recognize whether new things actually help or just some hot air... lots of hot air out there. understand how to observe the plant to make adjustments... Suggestions are a good place to start, but no matter what you follow, you observe and react to the plant in front of you. What "should be" doesn't matter if the plant is behaving differently than expected. Light - Nodes that stretch or are too tight will guide light adjustments. leaf symptoms will help adjust your fertilizer formula. read up on Daily Light integral and vapor-pressure deficit. You don't have to have a Ph.D in it, but should get the gist of each. The biggest issue i ssee with new growers is gotting lost in dogma. Most bro-science can be avoided simply by understanding fundamentals. e.g. any 'technique' that severely reduces leaf surface is highly unlikely to be a net-positive. Understanding what your limiting factors are makes this incredibly obvious, but without that morsel, can easily be fooled.

LIKE HINDUGOD SAID, I WOULD START OVER BECAUSE NOW YOU ARE WASTING TIME ON A PLANT THAT DOESN'T GROW. MAKE SURE NOT TO OVER WATER BECAUSE THAT IS THE CAUSE OF MOST STUNTED PLANTS. THANK THE MIGHTY HINDUGOD FOR HIS KNOWLEDGE ABOUT CANNABIS AND FOR ALWAYS TYPING WITH CAPS LOG ON!!!!!

DAT IS WHAT A 7 DAY OLD SEEDLING LOOKS LIKE! IF DAT IS AN AUTOFLOWER AT DAY 15 FROM SPROUT I WOULD CULL IT AND START A NEW BEAN!!!

coco appears to be on the dry side... make sure to water deep enough so the tap root can dig downward, if it runs into dry coco it will stop... use a water soluble rooting agent to help encourage rapid root growth... and being in coco you are in total control of every nutrient she will get, arm yourself with the proper tools(nutrients)and all should be good...happy gardening

hey 👋 She doesn’t look unhealthy, but it’s true that she’s growing slowly. Since you’re in coco, make sure to give her a root booster like Voodoo Juice, and raise the temperature a bit : 23°C is a little low. Also try to check what the nighttime temperature is; it might be too low.

For 15 days it's quiet small but it looks fine, the stem can go that colour and normally does in my experience