The short answer for Congo tetras
Feed Congo tetras twice a day, and be a little more generous than you would with small tetras: each meal should keep the school eating steadily for about two minutes, with almost nothing escaping to the bottom. Adults in a spacious, active setup hold their flowing fins and iridescent flanks best on that twice-daily rhythm. One meal a day leaves these big tetras lean and washes out the males; three usually ends up as water pollution rather than nutrition.
A tetra built on a larger scale
Everything about feeding changes with size. A Congo tetra grows to roughly three times the length of a neon, cruises the upper and middle water in long tanks, and burns correspondingly more energy. Its mouth takes standard flake, small floating pellets, and whole frozen foods that nano species cannot manage. Males in good feeding condition develop the extended, veil-like fins and violet-gold sheen the species is prized for, while underfed fish look plain and ragged by comparison. Judge the meal by the school's bodies: ribs should never show, bellies should swell modestly at feeding and flatten again by the next meal.
Variety that brings out the Congo colours
Run a quality tropical flake or micro-pellet as the everyday base, then rotate frozen bloodworms, black mosquito larvae, daphnia, and occasionally finely chopped earthworm through the week. Congos are omnivorous and appreciate a vegetable thread too — a spirulina flake day or a blanched pea, skinned and crumbled, keeps digestion moving. Feed the frozen portion thawed in a little tank water and spread along the length of the tank, because a single dropped cube triggers a scrum that the lower-ranking fish lose.
Bold feeders, quieter tankmates
Congos are peaceful but fast and utterly fearless at the surface, and in a mixed African or general community tank they can leave slower fish — angelfish picking carefully, shy rasboras holding back — underfed without any aggression at all. Feed in two places at once: the Congos' main ration at their usual end, and a smaller sinking or midwater portion at the far end for the rest. During the first weeks with new tankmates, watch entire meals rather than assuming the menu reaching the water is the menu each fish receives.
Overfeeding looks like enthusiasm
Because Congos attack food so joyfully, it is tempting to keep adding 'one more pinch' while they are still snapping — they will still be snapping long after they have had enough. Stick to the two-minute rule, siphon the substrate on water-change day, and watch for the slow tells of excess: thickening bodies, heavy waste, and a filter that clogs faster than it used to. A Congo that alone refuses food, loses its sheen, or drops out of the school's cruising pattern should be checked against water test results and, if it persists beyond a day or two, discussed with an aquatic veterinarian.
Two generous meals, one record of each
Hearty twice-daily feeding is precisely the routine that drifts when several people share a tank — everyone enjoys feeding the Congos, so the Congos get fed by everyone. Naming the feeder for each meal keeps the generosity at two rounds, not four. KinsLe's Care Teams sets that up for this school: morning and evening feeds are assigned duties, and each is closed out with a timestamp the next enthusiastic feeder can see.