1) IMO it wasn't a wiseguy answer. He's right. There will always be enough
algae for two ottos in a 55.

2) If you want to suppliment your ottos diet, you can use blanched spinich,
or blanched cucumber. No guarantees they'll come eat it though.
I have 8 ottos in a 75 and only one of them, the biggest one, ever comes to
eat the spinich. The rest simply ignore it.