Backyard Aquaponics
A place to discuss aquaponics

Anybody know a supplier?

In Queensland there are a couple of options - Grobest and Ridleys. Food comes in largish sacks (15, 25 or 30kg depending on size and brand) and costs a bit over $2 a kilo. I am not aware of suppliers in Canberra - but if you ring Ridleys - they may be able to tell you.

Try any local aquaculture producers who grow out fish, they will often sell you a bag or two at a decent price.