I was not intending the vinegar to be consumed directly by the sponges, although it is taken up by many organisms. I was intending the bacteria top be the consumer and the sponges eat the bacteria. Just as was mentioned above for corals.
this is also the reason I started, and have continued, to dose vodka. Not for nutrient reduction but only to boost the food chain for filter feeders. I have switched to all for reef and stopped vodka now so yet another doser head free.