Phosphate vs Phosphorus?

[alexeikathryn]

I am still learning the basics - What's the difference between phosphate and phosphorus?

 

[DaJMasta]

Phosphorous is an element (P) and phosphate is a compound (PO4), phosphorous doesn't really get talked about regarding reef aquaria much, so unless you're looking for specific chemical analyses or processes, they actually mean phosphorous if they're talking about most reef stuff.