Bactericide & Fungicide Questions

[chrisdclarke]

Hey everybody,
I have a few orchids that have rotten roots and I have a few that for no apparent reason will get brown/black leaves (mostly Dendrobiums section Spatulata). I also have a few that get Mealybugs and the little red spider mites (Phalaenopsis and one Dendrobium), which I am currently treating with a pesticide.

My question is whether most people:
1. use a Fungicide/ Bactericide regularly
2. use when a problem arises
3. think fungicides and bactericides shouldn't be necessary if the growing conditions for the orchids are suitable

I'd basically really like to know if me being new at this and being a little too eager is causing the issues or if everybody experiences these problems.

And part two of the question is does anybody have a few recommended brands of fungicide and bactericide that may be available in Australia and are safe to use on Dendrobiums? (extra bonus if somebody in Australia can tell me what to buy and where).