Benepets, in my experience can actually decrease PO⁴ levels due to the probiotics/bacteria esp
lactobacillus, bacillus, saccharomyces. these strains are highly efficient at uptaking PO⁴, they effectively uptake orthophosphates into their cellular membranes which basically make themselves little phosphate rich "food packets" for corals, those familiar with Zeovit systems and aquaforest centered methods should be somewhat familiar to this, even back in the early 1980s a fella by the name of Peter Wilkens stressed how important bacteria is to coral nutrition, which is probably why he was one of the first reef aquarists to successfully keep and grow notoriously difficult NPS corals like dendronepthya and delicate non-photosyntheitic gorgonians by daily sand stirring to "kick up" detritus and more importantly bacteria, into the tanks water column.
When I first started using benepets on grow out tanks, I was pretty suprised to see it actually drop measurable phosphorus levels, and some systems that have a particular high demand or run lean on N/P, I will add additional foods like oyster feast, rotifeast and phyto when feeding benepets to ensure PO4 doesn't run a chance of bottoming out.
