Pasted a couple of comments over to here Moonie... was going to suggest you start a thread...
Humidity and water loss through transpiration/evaporation are likely to be the two biggest problems you face..... powdery mildew will be a problem....
Keep as much airflow going over your plants as possible.... maybe even a couple of rotating fans....
You're going to need to shade everything through summer anyway... both for the plants, fish tank, and fish.....
You face a unique set of problems... but at least you can grow Barra all year round....
Given the amount of rain you can get in a short period of time Monnie... I'd cover the beds... for both that reason and the sheer heat of the day....
Collect whatever rain you can get though.... you'll probably need to do regular top-ups to the system as a whole... transpiration, will be a big factor in your system IMO....
