I "free feed" my eels live blackworms until they are big enough to take nightcrawler chuncks ( about 10" or so) by that meaning I get anywhere from a few "portions" to 1/4lb and add it to the tank everyweek. I add as much as it takes for them to be gone by the end of the week ( or appear to be gone) then add more... They grow extreamely fast and sleek. Once large enough I start adding nightcrawlers cut-up into 1/4s daily, and cut back on the blackworms until they are 100% on nightcrawlers... This is also when I move them from their own tank to one of my "communitys" from there I feed the tank normally.. pellets, frozen foods , ect... and hand-feed the eels their daily portion to ensure they are getting it ( most eels by then are accepting of hand/tong feedings) mine have all picked up frozen foods just by haveing it offered at normal feedings along with their worms. of course as they get bigger the more they eat and this is often when I will see my eels eating newer foods, when hungry but not starved or "fasted" to eat. Once nearing the 18" range ime most species can go days or weeks w/out food. so missing a few days is not anything to worry about, and I do fast my "adult" fish threw the weekends.