[He could be surprised, and he is, by the size she's implying. But when you attend Hope's Peak, you become more numb to ridiculous circumstances. As someone who was in charge of helping to do damage control on whatever the students chose to do to the campus, and then someone who was giving orders in particularly high-stakes situations later in life, his mind skips over the period of shock to the period of problem-solving.]

—We could dig a new artificial pond, but we'd need to account for proper management of the water, and of course that would be taking land away from any other projects we may have had in mind. If we want to keep them, we'll need to consult about the proper standards and dimensions, and their proper upkeep, before starting the project. For the time being, don't feed them any more leftovers. Fish can survive for some time without food, and there are natural sources of food for them available. If they lose weight that way, perhaps we won't need to move them at all.

[Luckily, in his way, and in a way that is probably true in the DR universe and probably true here too, he believes that the lovely Ultimate Housekeeper's Ultimate home cooking could never be poisonous to the fish or their habitat in any way. The concern is purely spatial.]