I heard the following about glassfish: "Hardy, mild tempered, needs some live food, can get fungus wo a little salt:" Then I got some. I wanted them to be crumb eaters after the big sloppy fish, but found them to be very aggressive against their own kind even w 5+ in the tank. They were poor eaters, chewed flakes then spit them out; and got velvet in the mouth. Is there a definitive answer about the pros and cons of glassfish?