2. Materials and methods
Juvenile sex-reversed all male Nile tilapia, 0. niloticus with mean initial weight of
23g + 0.7 and length of 11.5cm + 0.1 were stocked in netcages at 30 fish rne3.
Netcages were suspended in three 250 m* earthen ponds at the Asian Institute of
Technology West End Area, Bangkok, Thailand. The ponds were fertilized weekly with
urea and triple super phosphate at a rate of 4 kg N and 1 kg P ha-‘. The 13 mineral
treatments were allocated following a completely randomized block design (CRBD).
Each pond represented a block and treatments were in triplicate.