Stunted resurrection!!

No. If it were that simple, we all would have been doing it for years already. There are no magic tricks to turn poorly grown plants into super croppers. Focus on where you went wrong to prevent it from occuring next grow.

You need to relieve whatever is causing the stress. There's no magic bullet that will just flip a switch by adding it. Coincidental growth, excluded. do you strip leaves? they all look tiny. can't see much, but it's not the only plant with some leaf symptoms, and that's not severe enough to cause stunted growth, imo. Could be a runt or more sensitive to the less than ideal treatment so far than the others. I find the greatest benefit to a more ideal nutrition and climate is greater consistency. Instead of 25% of seedlings regularly sprouting within 2-3 days, half do, etc... 25% of plants perform at a 50g/sq ft or better production or 50% do etc.. just making up the improved proportions. certainly don't have the sample size to give an accurate guesstimate on that stuff. killing the weak early on helps too. Not all plants that lag behind early on stay behind the entire grow, but sure does correlate.

After more than an half hour analyzing your diary, here is my diagnosis : -Plants were overwatered during all the growth : Listen, when you see like speed bumps between the veins of the leaves, leaves being droopy, stems and petioles turning purple, it is a symptom of overwatering. Overwatering kills the roots hairs, the main root shaft abords water and roots hairs absorb the nutrients. Adding nutrients in this case isn’t the best option. -Plants received more light energy than their photosynthetic capacity: Blasting non healthy plants under too much light, when the plants are already struggling to absorb the nutrients, particularly Magnesium which is the central ion in the photosynthesis molecule and the first link in this chain process, was more harmful than beneficial. Too intense light leads to magnesium chlorosis* and photoinhibition* (*google this to understand). You can diagnose the problem by looking at your leaves petioles and stems turning purple and clear stripes between the leaves veins. It’s the earliest signal where you can solve the problem before it gets worse. -Too many nutrients : Adding nutrients on overwatered plants thinking it will fix the problem is the worse thing to do. Nutrients build up in the soil, EC starts to raise and osmotic pressure in the roots reverses. This is where leaves tips start to burn. I will suggest you this video to understand what you did wrong, 1 and a half hour is the minimum required but still never enough to study plants science…. : https://youtu.be/_LTNA3O6JN0?si=kzIHVOdcNRMuM_r2