DWCHCanswered grow question 5 years ago Looks to me like a case of too much humidity combined with too much water in the soil,. When the plant is germinating, and setting root, if you're misting, cut your watering back.. otherwise the humidity at soil level is high enough to not need misting if you've domed them to keep up the humidity. Get some rootshield to help avoid root rot in the future, or another mycorrhiza inoculant, as well add a fan to move the air around periodically. By the looks of things you're almost in the clear now, but keep an eye on the little runt, he may still be fighting off root rot .. which is reversable if caught early enough..
also don't cut out he nutes completely, rather try feeding a 25 or 30% nute mix every other watering and get them going again.. plain water is good as they'll throw new root to find missing foodstuffs in between feeding.. looking good now from what I can see in the pictures..cheers! Keep it Green! DWCHC 👍👈