deficiancy of some sort

[seldomBLUE]

magnesium def.

I agree. You may have a chlorine issue with your water so let it sit for a few days or use bottled water. The ppm won't change much since it gives a reading of "total metals". Your Mg may be 50ppm while total metals is 200. Up your 200ppm water to 400ppm with Cal-Mag, up the mix the to 700-800ppm with ferts. Your pH and ppm are in a good range

You really need some drain holes around the bottom of that bucket. Just like Hydro, those roots need air.