Herb is getting picky

^^^ that's herb when he was a baby (and the only pic i have of him right now)...anyway, herb is an L200 purchased from a small independent LFS whose specialty is exotic plecos and i have dealt with them exclusively since my first 20 gal. when i was in grade school...his belly was fat when i bought him and he is still totally healthy one year later...the only thing i don't understand is he loved raw (washed) zucchini (not boiled/blanched/whatever) and then about a month later, he got sick of it...so i tried some raw yellow squash...and again...he loved it...for 3 months...so i gave him raw yellow potato...and he thought it was awesome...for 3 months :wall: ...so i tried raw red potato...and he liked those up until a few weeks ago...i started getting worried when i'd change out the potato and there was none eaten...so i broke down and went with the lowest moisture, "all vegetable" algae discs i could find...i know, i know...but he's eating them and i'm a little confused as to why he'd prefer some manufactured crap over real "live" vegetables all of a sudden...herb is (and always has been) very comfortable...so comfortable in fact, that he eats during the day and actually hangs out with my green cories...i have a 55 long with a fluval 305 canister underneath and 2 aquaclear 50 HOB's on top so there's more than enough filtration for the other 4 black skirt tetras, 1 white skirt tetra, 5 serpae tetras, 4 glo-light tetras, 11 neons, 4 adult and 4 baby cories, and 2 hatchet fish (who aren't from the amazon, but look cool up high in the water column lol)...oh, and an apple snail...oh, wait...AND 4 small zebra danios who are still alive that were used to cycle the tank when i originally set it up 3 years ago...water paramaters are where they should be...and i vacuum one half of the gravel, clean all filters (media and housings) and do a 25% water change every sunday...religiously...um...sorry...i'm totally rambling...if anyone can suggest some other veggies to try or maybe just some thoughts on the situation, i'd really appreciate it...thx...

edit : i forgot my 5 pristella tetras...whoops!

...yeah, he's an omnivore...he likes bloodworms and shrimp pellets too...i was just wondering why he's boycotting the veggies...thanks for the advice, though...i'd probably get sick of the same old stuff like he must be lol...

...i'll post more pics of herb soon...he goes from dark green to almost neon green depending on what he's eating...