Hanna phosphate checker up to 0.79 2 days ago 0.41 a week before only 0.15

[vienna]

I'm worried the phosphate has gone up so suddenly.
Is this a bad reading? I'm considering buying a GFO & Carbon media reactor. I already have an octo bio pellett reactor and chaeto Growing.
I am feeding too much? Could using Bio enhance and coral essentials coral nutrition a and b cause high phosphate? That's the only new thing I'm doing

 

[blaxsun]

I'd reconfirm these results with a test at your LFS or through a titration test kit (Salifert, Nyos, etc.)