Stick with real food... market shrimp...hunks of meat...Krill...ect. Read the second line in my signiture very carefully because it's the truth.
I should probubly add that it's not a good idea to stuff your RTC like a football every night. Once Lucy reached about 10" long I started feeding her every other day. There's nothing worse in an aquarium than a 'powerfed' RTC that looks like a basketball with fins.
You do realize I trust just how big a RTC gets and more importiantly....how quickly? Don't get me wrong..I LOVE RTC's but I see far too many of them abandoned or returned once the reality of owning one sinks in. I have a series of tanks all ready for my RTC and the new baby...MRTC up to the 4'x4'x3' beast that should last until we get moved and build the monster tank.