recently i have been noticing that a lot of my plants are starting to get holes in the leaves, new leaves are coming in yellower than usual, old leaves get ragged and new leaves on my e. tenellus just disentigrate. ive narrowed my deficiencies down to potassium, iron, and nitrogen. i will take care of the potassium with greg watson ferts, but for iron and nitrogen i need some recommenations on what i should dose/add so i can have beautiful plants again!! thanks!!!