Hawi has just about perfect weather: Not too hot, not too humid like Hilo. Some of my friends retired there and I went to visit. Lovely place. In June, day length only gets up to around 13 hours so you might want to plant in a place that has a light you can turn on around midnight for 15 minutes. That fools the plants and keeps them from flowering too early. Then in August, you can stop with the light and let them follow the natural day/night cycle.
If you plant indicas, give them a little shade (like shade cloth) so they are not in direct sun from 10 to 2. I grow in San Diego and last summer I sunburned some indicas, but the sativas did fine in direct sun.
Several folks here use organic fertilizers and soil. Look at the forum topics to find organic threads. Fish pond water might be too weak. Aquaponic people need to keep all the nutrients for their own plants, so unless you want to raise your own tilapia you may have to just buy stuff. By the way, aquaponics is hard and expensive. Most commercial operations barely squeak buy selling their gourmet organic lettuce to restaurants. They end up with $20 a pound tilapia so it’s better not to eat the fish and just let them nourish the plants.