Cyano with no nutrients?

[Arok3000]

I had a bit of a cyano problem and a lot of a caulerpa problem.
My tests indicated zero on everything, but I doubted them and bought new kits just to find zero across the board.
Ended up swapping my old t5's out for LED and the problems cleared up quickly.

Since you're already running a Radion my circumstances don't really apply to you and I'm just consuming bandwidth. But maybe too much sunlight or red from the Radion?