Any idea why the lower leaves below the fan leaves seem to be dying?

[UndergroundFarmer]

Yep. Whichever bottle (A or B) is the "grow" nutrient, your plant needs more of that - assuming that there is no pH lockout happening.

[Tedtheclown]

Looks like it isnt getting N

[dilvish]

looks like a nitrogen deficiency but based on your grow set up info it could be too much humidity (up to 80% is too much). I also looked up your nutrients and I was surprised to see that the Shogun nutrients don't list the NPK values on their website or at least i couldn't find them.

How often do you water? what is the PH of the water and or water+nutrient level? You need to provide more information in this area. FYI when growing in coir, you need to start adding nutrients right way, making sure you test the PH of the water AFTER adding any liquid nutrients. You should also be flushing with plain PH'd water at least every third watering just to ensure there is no build up of nutes.

[Beginnersprouter]

Hey so I came to check my plans this morning and over the last couple days this one hadn't looked so healthy and now it seems dead to me, could this be due to it not getting light as the fan leaf is covering it? Could it be due to salt build up in the Coco? Could it also be due to some form of infection or excess amount of nutrients etc? Any help would be greatly appreciated, thank you growers!