Not every fish in an aquarium eats algae. Presumably they're just buying a trivial amount to feed a few particular fish.
Did you expect it to be anything other than a publicity stunt? Well, you're the kind of person who can be sold $2,000 in feed per year for 10 goldfish, and hold AEB shares, so I suppose you're open to all sorts of stuff.
...I used to breed a large number (hundreds) of tropical fish and I didn't spend that much. There will be much cheaper options, probably better than the overpriced crap you must be buying at pet shop prices. It definitely doesn't cost $2,000 a year to feed 10 goldfish!
AEB Price at posting:
1.9¢ Sentiment: Sell Disclosure: Not Held