I’ve changed my mind about how we’ll use fish waste as fertilizer for hydroponic vegetables. Instead of using the University of the Virgin Islands-developed high-tech aquaponics system, I’ve decided to use Roy Tanaka’s simple “rubbah slippah” system.

The University of the Virgin Islands concept is a recirculating system using a series of pumps, aerators and bio filters. Very elegant.

But then I visited Roy Tanaka, who has been using a run of the river at his place near Papaikou for many years. He uses a small pipe which runs from a nearby river into the first tank, and then overflows into a second tank and so on. It is the essence of simplicity and common sense. He tells me that he has never had to wash his tanks because they are always clean. Free water, no electricity for pumping or aeration and no need to clean the tanks. What’s not to like about that system?

We will take a little water out of the pipe that fills our reservoir and run it through several species of aquatic animals. We are thinking of trout in the first tank and tilapia in the second, overflowing to catfish in the third, prawns in the fourth and finally crawfish in the fifth. Then, the nutrient-full overflow will go into the reservoir that supplies water for our hydroponics operation.

The effect is that we will borrow water ahead of the reservoir, run it through the fish and then put the nutrient-laden water back into the reservoir to feed our hydroponic vegetables.

We plan to start small, producing fish for our employees. As we learn about the system’s limitations, as well as what the demand might be for our products, we will increase production. We don’t, however, intend to reduce the amount we provide to our workers.

I have the utmost respect for small innovative farmers. Roy Tanaka is a perfect example of a wise and practical farmer.