leaf problem what would it be cheers

Phosphorus Deficiency/nitrogen deficiency which means you need to check your pH you don’t have a way to read your pH in the soil then make as much pH water as you can and run it through and test the runoff water pH if it’s much lower or higher than what you put in you know you have a PH issue flush the crap out of it with the pH water don’t overdo it but flush it good then re-feed it soft on the notes about 50 to 75% strength