GH Bloom requires GH Micro for completeness.
RO and dehumidifier water requires CalMag for hardness.
No fish emulsion.
Your pH is too low for a soilless grow; bring to about 6.4.
Coco should be used with coco nutrients, or at LEAST with a calcium supplement(calmag, whcih you should be running anyway). It scavenges Ca and leaches out K.
If you do not have at least one gallon of medium for each foot of main stem, you are probably rootbound, and the plants look it. That would also contribute to the yellowing and poor soil chemistry.