Minimum basin size for Orinoco Altum 120 x 60 x 60 cm - better would be bigger and higher! Water change weekly 30% for optimal growth to keep bacterial density low. Feeding 3-4 times daily for juveniles with frost feed, white Mülas, Artemia, red mulas and water fleas, additional flake feed, For example, tetra min or granules, B. Dupla Rin. Orinoco Altums can reach a span of 25 - 30 cm within 12 months with good water quality and optimal feeding! The Altums can grow to within a span of 35 cm with a bra of 60 cm within three years, in bra with 70 cm and more to reach a span of 40 cm and more. They react very sensitively to high bacterial density in the basin. My Altum NZ swim in the tap water PH 7.5 KH 4 LW 280 ms and temperature 28 °.