Why two plants are going bad, but not the others 4 ?

I have similar issues with one of my grow - I liken them to Goldilocks and the Three Bears (although I only have 3 plants)... They all suffered from nitrogen toxicity a couple of weeks back and I had to flush and, at the same time, decided to change up the nutes as I was NOT pleased with what I had been using. One plant has continued to suffer but is at least producing some flowers... the second plant is doing better but still has signs of nute problems... the third plant seems to be saying "What nutrient problem???" - They're all individuals and they all need to be treated individually. I'm going great guns with the gal that has completely recovered from the issues... the second one, I'm still babying a little bit, cutting down on a couple of nutes and she's starting to respond... the third lady, the hardest hit lady, I'm treating with some ReCharge to try to get her roots to grow and strengthen - she doesn't drink anywhere NEAR what the others do - so she's lagging behind in nutes as well... but it's all a matter of paying attention to what each plant is trying to tell you. The plants that are doing badly for you right now are trying desperately to tell you they are being fed too much and in the wrong concentrations.. First of all, autoflowers don't like nutes in their first week or two of life and when you DO introduce nutes to them, it should be at a max of 1/2 strength to see how they are going to react. Given all that you've been giving them, I'm not really surprised they're acting this way... what I AM surprised at is that you've got some that seem to be doing ok with it all! You've got to adjust the regimen for the ones that aren't handling the nutes... what I would do is to simply water them with pH'd water for about a week and then re-evaluate... My inclination, with these ladies, would be to start them out (after a week of water only) with 1/4 strength nutes... wait and see... if all is well, then you can increase to 1/2 strength... Autos rarely need full strength of any nute line - the nute line feeding charts are NOT written for autoflowers and with autos, less is often MUCH better for them. Good luck!