Nitrogen toxicity from feeding too much or too often, or both.
Watering every day is a no-no, you should only water once the soil has dried from the previous watering, and only once the soil is dry to about an inch down from the surface.
Feeding every three days in soil, even if only lightly, is too much.
In soil, a schedule of plain water/plain water/feed/plain water/plain water/feed is best, and so that your plants are only being fed every 10-14 days.
Soil "holds onto" nutrients quite well, so this is the reason for only feeding every 12 days or so.
Watering to run off is vital too, if you do not do this, nutrient salts will build up in the soil to toxic levels and cause burning, like your plants are showing the symptoms of. It is also the only way to know that water has penetrated the entire way to the bottom of the pot, where most of the roots are/will be going.
At this stage I would be only be giving plain water for the next 2-3 weeks or until healthy growth returns and not flipping to 12/12 until they have fully recovered too.
Once you resume feeding, keep in mind the time frame I suggested and I am sure thinghs will pick up.
Hope this helps, Organoman.