these are great Ls and I also have these. They have a great sense of smell and knowledge when food is present, so I would not worry. They are meat and vegie eaters so vary the diet, in the early stages prdominant vegie eaters. The Hikari or tetra wafers are good. I would drop in 2 wafers in the tank late evening 1hour before lights out and one on left of tank and 1 on right of tank to give all a chance. Also drop in zuchinni, brocolli and other vegies, you will soon see which they like, but remove these after 24hours. They also like to knibble on the aufwuchs on the wood. Good luck with these.cheers jk