Feeding Picky Quoyi, Supplementing Food Help?

[Frigideus]

A few months ago I started my tank, and everything seems to be going somewhat smoothly. About a month ago I lucked out on a juvenile Quoyi from the LFS and risked getting a pickier fish despite little experience with picky fish (I haven't had a tank in over a decade). While I will need to upgrade my tank size for when he gets bigger, right now it is a matter of if he will make it that long. The fish seems happy otherwise, but I have noticed when it needs to poop it kinda gets erratic and bumping up against stuff, almost like it is constipated. When it comes out it also comes out sometimes just looking like fish flakes, so I think the limited diet might be causing issues. The only thing I feed it is nori dipped in seachem garlic for a couple minutes rubber banded to a rock. I'm not sure if this is the play, but it will eat as many nori sheets as I put in, and from what I understand this type of fish eats constantly.

I need to know if there's a way to get him to accept other food, and how. I've tried feeding it fresh shrimp, clams, and silversides, but it doesn't like any of them. Perhaps if I dipped it in garlic?

Any and all advice is appreciated!

 

[Gumbies R Us]

#reefsquad

 

[Rocks reef]

How long was it at the LFS?
How big is your tank as Quoyi parrotfish get quite large.
They are omnivores relying heavily on algae with supplemental shrimp, mysis any meaty frozen foods.