Everything was fine until the bottom leaves started to yellow and fell off. I checked the res and it didn't drink as much as it used to. Then i flushed the res and added plain ph-ed water and left it for 24 hours. Then i flushed again, added new water with 1/2 strength nutes but ph rised up from 5.7 to 6.3 after 24 hours. Corrected the ph by adding ph down directly into the res and added great white directly as well. After those two application, the leaves started to droop and i immediately changed the res with new water with 1/2 strength nutes. Now my plant looks like this. How can i fix this?