i know i have already asked about putting nekko in a fish tank but just wanting your thoughts on whats best. Would he be better off in a rub (50 litre) or a tank 18"x20" ? He is 6 months old 15"long and in a starter tank. I just want him to be the happiest he can be because i love him. :-). All ideas / comments appriciated. Thank you. Debbie x