How to Grow Tomatoes in Aquaponics
How to Grow Tomatoes in Aquaponics. Aquaponic systems grow fish in a water tank and use crops such as tomatoes to filter the tank water before it returns to the fish. The crop gets its nutrients from the tank water. Due to the somewhat experimental status of aquaponics, as of 2010, and the initial expense and the wide variety of set-ups being used both for research and for commercial production, you should have aquaponic systems professionally installed. Once set up, growing tomatoes in an aquaponic system is simple and highly productive.
Raise tomato plants to seedlings or purchase tomato seedlings from an organic grower. Avoid using any pesticide or fertilizer in seedlings for your aquaponic system.
Use growing media in your aquaponic growing area. It gives tomato roots better support than free-floating systems. Insert stakes into growing media. Use ties knotted to the edge of the growing area or lay a metal screen over the media surface to anchor the stakes upright. Tie stakes to the screen. Alternatively, suspend ropes or nets from a frame to support growing tomatoes.
Test the pH of the growing media and the water coming in from the fish tank. Aquaponic tomatoes grow best in this system at a pH of 5.8 to 7.2. Adjust the pH with fish-safe aquatic pH stabilizers if necessary.
Transplant the tomato seedlings once the pH is stabilized. Cover the root ball with a light layer of the growing media to help prevent the surface roots from drying out, unless you are growing the tomatoes in compost or other heavy media. Heavy media on top of the root ball will suffocate the top roots and promote disease.
Add red earthworms, also called red wigglers (Eisenia foetida), to the growing media to reduce anaerobic areas that are unhealthy for tomatoes. The worms also enrich the growing media with minerals and organic matter that the plants can use for food.
Monitor the phosphorus levels in the growing media and the incoming tank water weekly near tomato bloom time (about six weeks after transplant) and throughout fruit set. Add organic aquatic phosphorus fertilizer at the package recommended rates if phosphorus rates are low.