mixing different types of GFO?
 

i have a 2 little fishes phosban reactor with carbon in one and opti phos in the other my question is..... my opti phos has been regenerated a couple of times and everyone raves about rowi phos so i bought some

question since i have some opti phos in the reactor and its starting to dwingle down can i mix some rowi phos in at the same time or should i remove the opti phos first??