Probable phosphorus excess nutrient block

In water grows, they recover in 2 to 3 days. Just make sure you run some plain 5.8 ph water over your clay to release any built up salts in the clay. Then for the week your in and if their photos, then your good at 5 to 600 ppm 1 to 1.2 ec for now. If you see good growth next week, then up them by 100 ppm. Do this every week until you hit 800 ppm 1.6 ec. If their autos, cut them back to 400 ppm and up the same way until you reach 600 ppm