Nutrients

The damages that you're seeing currently arent from over feeding but rather over watering. Dial your nutrients to half strength and decrease your water, your medium will slowly start to dry up and your plants will start to grow green leaves again. Remember that sickly plants will not absorb as much as plants that are in good health. I may also suggest to get yourself rooting agent such as great white or voodoo juice this will encourage your roots to not only recover quickly but they will explode in mass allowing your plants to take up more water. As for tips on a 2-3 day feed, I would suggest the next time you start plants start them in solo cups, I would also suggest a ratio of almost 50/50 coco and perlite for the whole grow. The reason i suggest solo cups is roots tend to develop faster leader to better growth over all. Its a good starting point to be able to transplant them into their next homes. Having your mix nearly 50/50 allows you to drench the medium until you get run off but it also dries up fairly quickly and carries lots of oxygen in the medium, this also allows for better root growth and over all plant growth. From the solo cup I usually go to a 2 gallon then either a 5 or 7 to finish. If you have good ventilation good temps and youll see that youll be watering every 2-3 days in veg and every 2 days in flower. Hope this helps you on your journey to becoming a great grower! -The Projexx