too much light??

[martym]

Yes it is 2 actinics.
I have been running these lights for 2-3 months now.
Test kits are Eslo and salifert, PH probe, Hanna PO4, and a refractometer.
I was using IO but have slowly been changing to RBS. The coloration was happening before the switch, which is why i switched.
I am also using the zeovit system so the nutrients are low to nil.
What else shouls I be testing for?
Potassium is reading 530ppm