I wouldnt put olives in the tank either. Along with the sodium, you have oils too. Olives are not a natural diet for fish.. and I wouldnt try to introduce them to human food...

It just doesnt make sense to do that... IMO

~ kate
Ps.. NOW.. have you ever rolled an olive to your cat? lol... Now that is funny! for some reason my cats go crazy for the olives, and not just the fact that they roll, its something about the smell of them. Try it and see... lol.

~ kate