Dilute the nutrient solutions in a gallon of water before adding to the system. The water should always be clear after application. Initial nutrient solutions reference points:
- w:hoagland solution
- non-hydroponic fertilizers - use 1/10 of the label dosing, with the amount of water in the container in mind
- hydroponic fertilizers - labeled directions
- sterilized soil - sterilize fertile soil, then run it through a cheese cloth
- pH meter readability and EC by a multimeter
Potting soil may be sterilized by heating in a covered container. This same soil can be run through a cloth to fertilize the nutrient solution. Only a little bit is needed, and making the water murky is disadvantageous to the nutrient solution.
Initially, nutrient solutions or fish establishment of the water is necessary for aquaponic gardening. New propagation tissue, like seeds and stem cuttings, can tolerate the lack of nutrients, until the levels build up from fish wastes. Aquatic animals do the work of maintaining proper plant nutrition and maintaining salt levels. Once fish are established, nutrient solutions are no longer necessary for maintaining aquaponic gardens, since fish waste provides all of the nutrients necessary. Adding nutrient solutions after this point can be detrimental to the plants, while this may not readily affect fish. In an aquaponic system, adding less fertilizer is safer than adding too much, especially since aquatic animals immediately make up for the difference.
If the water is changed, the correct nutrient solution has to be compensated. Rooted or established plants may quickly die of nutrient deficiencies.
Supplements for plants
Aspirin, melatonin and rooting hormones may be beneficial to the plant.