Nisai Japanese Koi are second-year koi, usually showing more developed body shape and clearer colour pattern while still having plenty of growth potential. They’re peaceful, active pond fish that do well in stable, well-filtered systems with good swimming space and strong aeration. A minimum pond volume of around 3,000–4,000 litres is recommended for a small group, with regular maintenance to support their increasing size and waste output. Nisai koi thrive on a balanced, high-quality diet aimed at both growth and colour, and are best kept with other koi of similar size to minimise stress and competition.
