Tropheus are, for the most part, herbivores, and specifically algae grazers, which have a very long digestive tract, and need to be fed often, with the correct diet. Many foods that are good for most Cichlids can be harmful (over the long term) to Tropheus.

Tropheus are notorious for "bloat", an intestinal disorder that can be triggered by diets heavy in animal proteins. To minimize this, feed primarily algae based foods such as a good spirulina flake. During their algae grazing, they also ingest small crustaceans and other microorganisms, so a bit of protein is acceptable.You can feed a higher protein flake now & then, like Brine Shrimp flake or freeze dried Krill, but it shouldn't make up the majority of it's diet.

Try to feed often, I recommend 3x daily, or more if you can, but feed sparingly, about all they can consume in 3 minutes.

It's also a good idea to provide alot of light to encourage algae growth on the rockwork, your Tropheus will graze constantly, and it's quite a sight!
ขอบคุณล่วงหน้าครับ