Prevent Salt build up DTW

[Mike_3]

Growing in Pro Mix HP 10 gallon fabric pots. Running General Hydroponics Flora A Duo nutrients Drain To Waste. I’m giving my plants roughly 2.7 gallons having plenty of run off every time I feed. I have a drip system that feeds my plants however constantly having salt build up from my nutrients resulting in slow growth… how can I fix this? Any suggestions

 

[1989cheeseSOG]

if your runoff ppm measure more than the input you're overfeeding your plants
they transpire more than they eat and the EC in the medium increase

what EC do you feed at ?