Sandra - I have read comments from another person in Florida who has not had spiking phals yet either. Hopefully you will get some colder weather for them soon (not that YOU want it for yourself!).
PhalPal - besides my new T5 fixture I have SIX cheapie Home Depot/Lowes type shop lights - NONE of them buzz. I know what you mean though - in my distant past I have had buzzers.
As you look at those fixtures keep in mind what I said about T8 bulb fixtures - OK for phals and paphs - but not enough light for catts!