Is there a substantial amount of phosphate in fdff?? I have been feeding frozen brine shrimp for a few weeks and have not had to add any po4 since the addition of the brine shrimp to my fishes diet. I only feed the shrimp once a day (a minute portion by the way) and my po4 was at 1.5ppm today after a water change. I would imagine if the frozen foods were this phosphate rich (as they seem to be) it would be wise to avoid frozen foods use in a delicately balanced planted aquarium. Any thoughts??