Just out of curiosity what are the temperatures like... day and night?
Also... I just looked up mosaic virus in peppers and got some images looking alot like your plants.
Did you apply the mic during the heat of the day when the sun was beaming onto the plants? If so, this can stress the plants sometimes (creates thermal/water transport problems in the plant cell membranes... Potassium also happens to be something the plants use to fight moisture stress and...
This appears to be nutrient burn to my eyes. I would commence using only water to feed the plants... and consider flushing the plants out by placing them under a sprinkler... so that they have adequate water to deal with the ions.