From what I've found, the Murray-Darling drainage basin is connected to many other rivers such as the Baloone and the Condamine River. They are found in Queensland yes, but in connected rivers that fall under the Murray-Darling river basin. But obviously there is underground salt that leeches into the river, and in recent years has drastically raised the Murray's salinity. Maybe the underground salt deposits are only in South Eastern Australia. I have read that adding crushed coral/aragonite may aid in the buffering of the water, making it harder how the Cod likes it. This is what I do for my Bumblebee Grouper. He is in rather low salinity for a grouper, but because of the hardness, it helps a lot, although rather soon he will be in a higher salinity system. It looks like Vik and I may need to keep our guys in specialized systems, which I was actually planning on in the first place. I have some friends in Australia who are anglers so I'll dig deeper for an answer.
mike
