Brown Edges , Yellowing leaves

Here are the pictures.

What might be the problem .

probably root rot, your medium seems very damp are you letting them wick the water in the trays back up? anyway let them dry out fairly well before watering

they might be overwatered in the past. now I let them dry completely. actually I'm so scared of watering that before I water them they are all down like dead and then they bounce back.

I suspected root root , but was not sure . Ill trow them away than. Thank you for your answer.

oh yea the soil is dampn now since I was just watering them .

small seedlings have a small root system and once infected by root rot they don’t always bounce back from it. still i wouldnt throw them out.
i’d just water with h2o2 first and add some beneficial microbes into my watering regimen from then on and don’t let them wilt before watering either thats another form of stress, just dont water them while still damp.

Overwatering. Let the pots get almost dry then water until runoff and repeat. Don't let them get DRY but let them get where the pot is light feeling then water until some comes out the bottom.

Transplant into bigger container with dry medium and leave it alone for a couple of days. Then a half strength feed of whatever you use.

Does anyone know why wuld leaves turn purple ?

This is one of the flowers above that I overwatered. Rest are doing fine and are healthy but this one is starting to get purple leaves ??
Shuld I just take off those leaves ?