Coral is, if you pick a stony like hammer, or a softie like mushrooms and zoas and such, prolific and easier than fish. It doesn't jump, and it warns you (by contracting) when the water's not right. You do need appropriate light for a given class---Reef LEDS, T5 reef, or Metal Halide for stony, with calcium powder (kalk) in your topoff water (which automates that supplementation: stony coral eats calcium for its skeleton) ---or for softies, any of the light types but a little gentler than you'd use for stony. No supplementation, but run carbon, because they spit at each other when annoyed and carbon absorbs it. The types don't get along well together, but both grow. Several varieties of softie have gotten to the status of crabgrass, they grow so well: green star polyp, discosoma (common purple) mushrooms, and xenia. They can take a tank once they get onto the rockwork. Most people prefer something a little easier to control.