I am growing 15 small plants in rockwool cubes... I had a problem with overfertilization and so I flushed the plants all week... with 5.7ph water.The leafs stopped burning with brown leaf tips but now they are experiencing another problem. quite a few different plants have yellow leaves on the lower half and 3 have yellow leafs with brown blobs/chunks spots on them. I am really trying hard to save these plants they are 4-6 inches tall and a few have side shoots that are 1 inch but basically the plants are pretty small in stature. I dont know if the yellow is after effects of over fertilization or if it is a nitrogen defficiency? Can anyone help me?
Bro, next time you have a over fert issue, flush, but don't flush with just water for a week, I did that once, and I went directly from overfert to deficiency within those 5-6 days.. What you want to do is flush with water for a day or so, then add 1/4 strength nutes, this will actually help to flush out the rest of the salt buildup in the cubes the water couldn't... then after that gradually work your way up watching the plants reaction.. I'm sure they will be fine, too much stress can sometimes cause hermies but I doubt you'll lose the plants.. It may take a day or two for them to react to the nutes, but they'll kick in.. Just make sure you don't go overboard.. And by the way, with rockwool, I would advise that you flush it out every time you do a water change, simply fill the res back up and treat the water to a ph of 5.7-6.0 add a once or two of nutes( small amounts of salts disolve salt buildup) and flood them for a few hours.. This keeps salts from building up in the cubes.. Half the time you have a deficiency or burn symptom it's from lockout or overdose due to salt buildup in your medium..