what else

[300zx]

I currently have a pair of rays and a sliver arowana. 560 litre tank ( I know I'm going to need a bigger one soon) the top looks good and the bottom looks good, it's just the middle looks a bit sparse, any recomendations ?

ph 6.5
ammonia 0
nitrite 0
nitrate 12.5
I do a 20% water change weekly
no plants

thanks in advance

 

[CFC]

Ive broken the cardinal rule and mixed Cichlids with rays in the form of two oscars to occupy the space left in the middle of my tank, it works for me as my oscars are very passive and the tank is large enough for territories to not be a issue (800L).
Siamese tiger fish (Datnoids) also work well but their can be issues with keeping them with arowana's which seem to dislike stripey fish for some reason. Free swimming catfishes like Ageneiosus species and larger Pimeloids (lima shovelnoses etc) also work quite well.

 

[300zx]

thanks for the info, was thinking about oscars, discus seem to much work lol. Think i might shop around as they are going to have to large enough for the arowana not to eat them