Bud, I can give a guess as well as anyone else out there. You gave photo's which is very cool, but zero info on what conditions the plants are in. I almost could see what the temps were on the temp gauge.
Temps, PH, Humidity, type of lights and how much and how close. All the info you can think of.
One photo looked like heat stress, But after looking at all the other photos I do not think this is the trouble. You have SOME very dark green leafs, with almost yellow new growth. I think what you have done is over fed them or got the PH of the medium out of wack to where the plant is fighting to get the correct amount of each nutrient. It is like you were over feeding them, causeing the really dark green leafs, this cause salt build up which spiked the PH locking out some of the nutrients. But hey, Like I said. With out more information it is just a guess. Hell Like I always say, Aliens might have came down and piss'd on your plants giving them intergalactic space fungus.
Mre info would be very helpful, and check the PH of the medium or the Run off. If you get the PH of the run off make sure it is not from the start of the run off or the end. Get a good representative sample. If I am checking from run off, I usually get at least 1/3 of a gallon of run off and mix it, and sample that, never taking the sample from the very top of the water, where you get that microscopic film of stuff you can never see. It gathers there from surface tension. So put the little container under the water, swich it around then place your thumb over it. You get this info and someone will get you dialed right in. Those plants are very fixable. Either that or we could make sandwhiches out of them. lol they look kind of like fresh lettuce.
