How much nutrient is correct? Should there be a relationship between nutrient EC in vs run off EC out?

Hey looks like a potassium deficiency (burned and crispy leaves + yellowing leaves) +  I would increase nitrogen as well by a little bit If you are able to mix nutrients by yourself I would aim for something like NPK 4-6-5 PPM 1000 - 1200 (2.0 - 2.4) Regularity of feedings is also very important now: Feed with ppm 1000 on day 1 Only ph balanced water day 2 Ppm 1100 day 3... So you can see how your girl reacts to the new nutrient feedings and eventually find the sweet spot of how many nutrients your girl needs Don't think its nute burn cause leaves wouldnt turn yellow as well (nute burn = only crispy and burned leaves + No yellowing of leaves)

Hi there! Basically there is nutrient toxicities and nutrient burn. So you can give too much of one nutrient to have an toxiticy or everything too much and this will result in nute burn. Or if you give way too much something it will cause nute burn too and it can build up in soil over time. If you are feeding liquid nutes and you think all the nutes from soil are used then if the EC of the run off is higher then you have build up nutes in soil. Optimum level is the one where no deficiencies are shown and no nute burn or tocities ofc. The balance of the nutrients is also very important factor so you need to give right amount of everything and in right balance for the girl to grow happily