Quote Originally Posted by foodchain
I am confused on your salt ratio recommendations, and on the tilapia not being able to tolerate anything higher. My tilapia, now in for the winter are in considerably higher concentrations with apparently no ill effects. Also both the Univ. of HI, and the UVI are currently conducting studies on, and breeding programs for tilapia in brackish and sea water. I am sure I the PDF on that around here if you want it. I just have to find it.
No no no, I said Tilapia CAN handle highly saline solutions. Some tilapia species can handle hypersaline solutions, in fact.

However, some fish don't have much of a tolerance for it. You see, the histology of a Tilapia gill reveals it has specialized cells to handle the chloride ions that enter their body due to osmoregulation. Their internal body chemistry also adapts to the saline conditions. Try that with say... goldfish (just a guess) and you won't see anywhere NEAR the salt tolerance.