ann,
I live in Melbourne, grow a few cattleya alliance orchids, some indoors, some outdoors, and a scattering of Australian natives (Sarc, Den, and terrestrials). I don't fertilize at all. I gave my Cymbids a mild shot in the summer. That was all.
The cattleyas that have a lot of Sophronites coccinea grow outside and can handle the cool. The rest grow inside in a south window (no direct light) and they bloom too.
You cansee pics I've posted of my orchids here:
Orchids du Jour
I grow mostly slippers (Paphs) but there are pics fo my cattleyas and dendrobiums too. And I don't fertilize but only a very little.