Phosphorus is one of the plant’s primary nutrients in an aquaponics garden and it is important to maintain the proper levels.
Because it is seldom deficient phosphorous levels is often ignored by aquaponics gardeners. When phosphorous levels are not high enough during the flower and fruit production stages the yields will be down. It is not that the phosphorous is deficient it is that the level is just not high enough.
In all the ponds and waterways plants and algae is seeking phosphorous during their growth and production cycles.
One reason tomatoes and peppers may be producing small amounts of produce is a lack of phosphorous in the water that feeds the roots. This can happen when the water is rich in nitrogen.
Even though nitrogen is by far the most important element for the growth of leaves, stems, and roots of the vegetables phosphorous and potassium are important during the setting of flowers, seeds, and fruits.
Phosphorus for Aquaponic Garden
For aquaponics gardeners that want to grow tomatoes, peppers, and cucumbers you may have to supplement the levels of phosphorous in the water.
The least expensive way to supplement phosphate is to use natural rock phosphate.
Rock Phosphate
Rock phosphate in the form of granules or dust can simply be sprinkled on the top of grow beds when the vegetable and fruit plants begin to flower. It will release very slowly phosphate into the water solution.
When the granules are added correctly most of the phosphate is consumed immediately by the plants. Only a small amount will bleed into the water supply.
A number of aquaponics gardeners actually separate the fruiting and vegetable crops in a different part of the aquaponics system. This is because fruit plants produce better in grow beds whereas vegetables seem to grow and produce better in vertical aquaponics towers.
Adding Phosphate To Fish Tanks
When you supplement phosphorous into the system you will need to keep the fish tanks in the shade. Phosphorous can cause algae blooms when the fish tanks are unshaded. The higher the levels the more algae blooms will be produced.
When phosphorus is managed in a healthy aquaponic garden fruit and flower production will increase significantly.
Phosphate Levels in an Aquaponic Garden
A good level of phosphate in an aquaponics garden is between 10 and 20 ppm for vegetable crops and between 20 and 40 ppm for tomatoes and cucumbers.