All plants showing issues all connected to same RDWC res first time posting but any help really appreciated.
If you don’t have a growlog please answer these questions.
What strain are you growing? Is it Auto, Fem or Reg?
Are you growing Indoor or outdoor?
Are you using nutrients? Which ones? How much?
Could also be a Magnesium deficiency. So you might want to get some calmag. And what’s aways good too have in the fertilizer repertoire is some Vitamin B, which makes the plant overall healthier.
Are your nutrient levels, EC and pH rising, falling or static? I no longer mess with DWC but do remember that there are 18 possible states that can help diagnose and solve issues in recirculating systems.
This an old chart that covers possible causes/solutions based on these states.