Just a clarification: EasySPS is NOT phyto. It is "a premium mixture of natural marine plankton in a mineral suspension" according to their description. EasyBooster is the phyto product.
The idea as I understand it is that Easybooster provides phyto for the lower end of the food chain, ie copepods while the EasySPS is supposed to be coral food.
I have no doubt on the results I have from dosing Easybooster. My copepod population has increased by a lot (I've been dosing it for several years now). And my Mandarin is very fat!
However I can't confirm that the EasySPS actually adds to the health/growth of SPS corals (I've been dosing that for several years as well). I'm starting to suspect that it may have less benefit than I initially thought and that it does add phosphates to the tank. I have reduced the dosing of this product by about half and do notice a decrease in phosphate levels in the tank while I still can't keep up with the growth of my corals.
I will decrease even further my dosing of EasySPS and see what the results are. If phosphates continue to decrease and corals continue to be very healthy I will then stop dosing it and see what happens.
But for the EasyBooster, if you do not have the time/energy/equipment to culture your own live phyto, this is an excellent alternative!!