Sure puts a different slant on the expression "drinking like a fish", for me anyway.
I am so sorry that you are going thru this totally, weird experience, and for having to care for the family on what you can get....after the fish are fed and catered for.
Could you tell him, that if he leaves you short of food money to feed the family, it will be fish and chips for tea........very fresh fish, and give the biggest tank a long look?
Could I send him a White Pointer for his collection?