[degordon3000]

Thanks Diana. Not too worried about the illness. At least I know now (since buying your book) that the environment of my tank is ok - it's bacteria that is the problem. I'll euthanize the affected platties. Unfortunately the option of putting them in the freezer (which I've read somewhere) is not one that I can use (my wife isn't keen on dying fish being placed in the freezer). I'll look on the forum for euthanasia options.

Thanks again.

David