An angelfish chases along lines it can see. Once the fish it is pursuing rounds a corner and disappears, the pursuit usually loses its point, because the territory being defended is a visible patch of water rather than the whole tank. That single fact is what makes a small fix work: you do not need new rockwork or a different layout, only an interruption placed where the chased fish already flees.
Break the Line of Sight First
Start by watching two or three chases and noting the route the smaller fish takes. Most chased fish run the same path every time, often toward one corner, one plant cluster, or the back glass. Place your interruption directly on that route: a tall stem plant, a sword plant with broad leaves, a piece of driftwood stood upright, or a cave ornament shifted a few inches so its opening faces away from the angelfish's corner. The goal is a visual wall at the halfway point, so the fleeing fish passes behind something solid-looking and the angelfish arrives at a blank screen of leaves instead of a target.
Give the change a few days before judging it. A chased fish that learns it has a reliable disappearing point usually starts using it within a day or two, and the angelfish often stops launching chases it can no longer finish. If chases still end in nipping, add a second break on the other common route rather than rearranging everything at once, so you can tell which change actually helped.
Feed in Two Places at Once
A territorial angelfish guards food as readily as it guards space, and many chases that look like pure aggression start at feeding time. Drop food at two spots at the same time, one near the angelfish's usual corner and one at the far end, so it must choose a station instead of patrolling the whole surface. The chased fish eats at the far spot while the angelfish is occupied, and that daily truce often lowers tension outside feeding time as well.
Note who is doing the chasing while you watch these feeds. A single pushy fish behaves differently from a bonded pair defending a corner together, and a pair that has claimed a spawning site will chase harder and from a fixed base. A pair calls for a wider cleared zone around their corner and feeding spots kept well away from it, while a single bully usually settles once sightlines break and food stops being worth guarding.
Share the Watching Brief at Home
Chasing is easiest to judge as a trend, and trends get lost when each person in the house watches a different slice of the day. This is where Care Teams earns its place for this tank: at each feed, one named person drops food at the left spot while another drops at the right spot at the same time, and each feed doubles as an observation duty. Whoever feeds notes three things in the shared record: how many chases they saw, whether the chased fish used the new cover, and whether any fin edges look newly torn. Completed duties are marked with a timestamp, so a gap in the notes is visible instead of silent.
Work from that shared picture when you decide the next step. Three calmer days in a row suggest the sightline break is holding. Chases that continue but end at the plant wall are progress, not failure. Torn fins, a chased fish hiding through feeding time, or weight loss in the smaller fish mean the small fixes are not enough for now: slide in a temporary divider for a few days to let fins heal and stress fall, then remove it and watch the notes for whether the truce survives. Families who keep those feeding spots and damage notes aligned inside KinsLe, recorded under Care Teams for this tank, spot a relapse days sooner than memory alone allows.