It's BLUE !!

[Mooner]

Just received an order from AquariumFertilizer.com and the mono potassium phosphate is blue.

They sent a note that says there is a worldwide shortage of MKP. This particular brand of fertilizer that they found was meant to be a foliar spray. They say it's just blue food coloring and is harmless.

Interesting...

 

[Tom Barr]

Since it's a foliar spray, the color is used to determine what has been and what has not been sprayed with ferts. Same thing with contact herbicides, that way you knwo it got hit.

Regards,
Tom Barr