First ... find a suitable soil STAT......Typical Bagged mix from large garden centers ... no real nutritional value to your plants.
It comprises Almost entirely of Pine bark , perlite and peat With “ some “ kind of fertilizer, probably pelletized like Miracle gro.
It is some an early magnesium deficiency. Intervein yellowing .
Find a local nursery or a hydro shop for better bagged like Happy Farm , Kelloggs organic , Dr. Earth potting , Mother’s Groundswell ( ace hardware ) , fox farms .... these are loaded with better elements for growth and some have thriving microbial life.
Fox Farms OF will grow on water only for at least 5 weeks .
Dr. Earth has vey good soil and a excellent dry fertilizer line too.
You can also run promix but will have to feed into it. Like with Dr. Earth life / homegrown. Megacrop will work too.
Flat out it’s the medium.