m0useanswered grow question a year ago I have not heard the phrase "84 and door" before but it sounds neat, I don't think its a golden rule though.
Your plants are looking a bit overfeed at the moment and that discoloration could be from a bit of a salt buildup in the soil locking out some nutrients or a lack of some other nutrient not related to a buildup. Its mimicking Potassium deficiency,
Also to much Nitrogen as Nh4 with low amount of NO3 will lock out potassium. magnesium and calcium. This is what its looking like to me, but play aorund with your nutrients and maybe lessen up on the N and try and get some runoff with your next water to leach some of it out. Be careful not to water to fast with soil as it can compact it and cause other issues.
Good Luck!