PAES W.A.T.E.R. Harvests Plants from Aquaponics System
Published on Jul 11, 2018

The PAES W.A.T.E.R. aquaponics system consists of four 800-gallon fish tanks where water is cycled through and clarified to remove the solids. From there, the water enters a series of biofilters where ammonia is converted to nitrate, and then the water runs through the plant beds. As the plants consume the nitrate to grow, the water returns to the sump. Although the majority of the nutrients come from the fish in the system, the PAES W.A.T.E.R. team supplements the water with iron, potassium, and calcium.

Laboratory Technician Melyna Silva harvests basil from the PAES W.A.T.E.R. aquaponics system.

Currently, the system holds 340 tilapia that weigh approximately two pounds each, and it is growing several varieties of plants including herbs, okra, peppers, eggplant and other fresh vegetables.

Leafy greens started for the PAES W.A.T.E.R. aquaponics system.

The PAES W.A.T.E.R. team recently harvested 135 basil plants and 180 heads of lettuce. All the plants were started from seed on the seedling table. From there, the plants are transplanted into floating rafts. Once they’re home in the rafts, the lettuce and basil will take around 3 weeks to harvest. We will continue to plant more leafy greens to harvest throughout the year.

The floating rafts allow the plants to reach the nutrients in the water below.

Given that this is an aquaponics system, the team is careful not to put anything in the water that could harm the fish or plants, so no pesticides or chemicals are added to the system. Biological controls like lady bugs can be used to feed on any unwanted insects. Methods of biological control are generally better suited for a greenhouse or indoor environment where they are not able to go feed on other insects in the wild. The team relies on the following methods to deter insects from feeding on the plants:

• Natural soap. One cap per gallon can be used to control white flies and Aphids.

• Neen oil can be used to control Aphids, white flies and powdery mildew

• Garlic. 1-2 cloves per gallon can control Aphids

• Cayenne pepper extract. 1-2 teaspoons per gallon

In terms of a specific product, PAES W.A.T.E.R. prefers Organocide, which is 85 percent fish oil-based and very safe.

The PAES W.A.T.E.R. team plans to continue to operate the aquaponics system throughout the year by planting certain species of plants for the summer and winter months. The system was originally built in the August 2009.

Melyna Silva, laboratory technician, harvests leafy greens from the PAES W.A.T.E.R. aquaponics system.

Looking to start your own aquaponics system? One tip to get the most out of your system: Use a simple design where you can use gravity to your advantage. The PAES W.A.T.E.R. aquaponics system is operated by a single pump and the rest is gravity feed throughout the system. This limits the amount of mechanical issues that can occur, as well.