If you can't find nightcrawlers you could use trout worms (mini version of nightcrawler) I used to feed them that, also try krill. If he wont eat the pellets you have you could stuff the fillet with the pellets and feed him that way.
And 82 degrees might be a bit too high. I have mine set for 78-79 degrees and that's when he does perfect.
Also not trying to flame you.... But when do you plan on getting a bigger tank because in about 5 months he will be the width of that tank or more....