feeding response vs irritation

In SPS corals that slime up, is there a way to differentiate between a feeding response and irritation?

Yeah I thought so too. Unless the coral is kept in a controlled environment and the "food" is introduced after figuring out what the intrinsic growth rate of the coral is (by weight of the coral, after say a month in the controlled environment and noted as weekly growth rate). Then checking if there is any change in weight of the coral more than its intrinsic growth rate after a month of adding the food to the controlled environment (and making sure that the free foating food is removed so the coral doesnt get nutrients off the decay)

Hmm yeah, you're right. We could show if the growth rate doesnt change then the coral isnt internalizing the food and therefore is just showing an irritation response to the food. But yeah it cant serve as its own control, unless we show a different growth response to a different food.