Cyano outbreak with new lighting

[saltyj]

I had some old bulbs in my Coralife PC fixture and had some "red sand" issues (not cyano) I recently replaced my bulbs and now I am noticing cyano on the LR and glass. Is this common when replacing bulbs?

[Masoch]

PC lights don't age welland rapidly lose their PAR. When you replaced your bulbs, all of a sudden, there was once again enough light for photosynthesis to kick in and suck up whatever fertilizer was available in your tank.

And, yes, it's a common occurrence :)