Feeding questions that are not tied to one brand: what your source water already contains, what pH and electrical conductivity actually tell you, the order things go into the tank, and which of the biological additives on the shelf do something measurable.
Anything brand-specific has its own sub-board under Fertilizers. What collects here is the part that stays true across all of them, which is most of the diagnosis: a nutrient that is present but locked out by pH looks exactly like a nutrient that is absent, and a root problem looks like a leaf problem for about a week before it announces itself.
Two things make a thread here answerable. Post the numbers, meaning source water, input solution and runoff or reservoir, because a photograph of a yellow leaf without them has perhaps four plausible explanations. And say which substrate you are in, since peat, coco coir and a recirculating system each punish a different mistake.
Where to start
- Pre-Harvest Flushing: Science or Myth?
- What Is a Biostimulant?
- Mycorrhizae, Trichoderma, Bacillus: the Root Microbiome Arsenal
Related elsewhere on the forum: Nutrient Deficiency and Toxicity: Reading Your Leaves in Fertilizers.