Tom writes: Exchanging Ca with Na did not work for me at all. My fish just gradually withered away. R/O works well and if you start with good water it is even better. Tom Tom--Based on your email id and location my guess is that you are the doctor in Chico that Brian Wolinski told me about a couple of years back when I was looking for Nijsenni. Brian said you seemed to be doing a pretty good job of reproducing Nijsenni. How hard is your source water before you used the Na+ for Ca+ ion exchange water softener? Would you mind giving some detail on your success at breeding Nijsenni? I'm always interested in hearing how different people achieve success at breeding apistos. Ed Pon Milpita, California 95035