Please help; Why are my lower leaves turning Yellow

During Veg - Neem or Wettable Sulphur sprayed on both sides of the leaves will take care of the mites. Added some likes to the feed them and Nitrogen comments haha, but that actually looks like a Magnesium deficiency. Coco continues to gobble a share of double charge ions like magnesium, as the fibres break down, exposing fresh cation exchange sites.

Well I just found out that I have tiny red spider mites that have been eating the green out of my leaves(chlorophyll) any suggestions?

I’m doing 6ml of micro & 9ml of bloom

Give her some food, some sort of micro/macro blend of N-P-K start at half strength and see how she likes it. Hope this helps!

I think you need nitrogen. You say you are using 7mL Micro & 9mL Bloom per gallon, but are you using any Grow? That's where most of your nitrogen will be found to complete the tripart nutrient solution.