found this on another site about rinsing food

[SeaHorse_Fanatic]

It's NOT just phosphates I am trying to reduce when I rinse my food before feeding. If I was using the little cubes, then maybe I wouldn't bother and just toss the whole cube in the tank. But I use the big blocks and break off good sized chunks which would add significantly more pollutants into my tanks without being rinsed.

[gregzz4]

I use the big packs too, and will keep rinsing before I cube and freeze
My reasoning for rinsing is that the 'free' phosphates added through the 'juice' is only fuel for algae, not critter food
Whatever phosphates are actually 'in' the food will be processed by the critters eating said food