How big did you get them? I got one last month, and it is about 5" now. I find them notoriously horrible eaters like small Jurenses. Believe it or not, but I found it helped getting a small RTC to encourage it to feed, as it seems to only feed when the RTC comes close, upon which it chases the RTC away, then eats what I had dropped by it. Gonna bring the RTC back to the LFS soon, as it had a HUGE jump on my Tig (which I knew it would, was just looking for a temporary tankmate to encourage feeding).
I am feeding mine raw shrimp (de-shelled), krill, brine shrimp, and I have been trying to feed it small pieces of fish fillet (stickleback), which it refuses still. I am starting to get worried that it is not eating fish, and I really refuse to feed it feeders (lost my Jurense after 3 successive feeder purchases). I want to get mine to monster size like yours, and I would be happy if it had half the appearance!! Suggestions welcome.