Richard bray

Mineralization Tanks
The bacteria that break down solid waste need surface area to colonize. This is the purpose of the mineralization tanks. They are large tanks filled with a media that provides a large surface area, and as solid waste flows into the tank, it is trapped by the media and begins to decompose.
The difference between biological surface area for nitrification, and biological surface area for mineralization, is that nitrification works on the ammonia in the water, while mineralization works on settled solids. The surface area on the sides of a grow bed does not help with mineralization, because there’s no buildup of solid waste.
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Macro and Micro nutrients
Frequent water testing will help to keep your system balanced. Each nutrient is necessary for certain plant functions, and each one can cause problems if it is outside its optimal range.
Potassium
This nutrient is responsible for communication between plant cells, and it regulates many chemical processes. It’s also the most common deficiency in an aquaponic system, since fish feed is not manufactured to keep up with the needs of plants.
Mineralization will only break down the elements that are already present. If fish feed is lacking in certain nutrients, no amount of mineralization can make up for them. Therefore, if you are using an aquaculture feed instead of an aquaponic feed, you will end up with potassium deficiencies.
There are a few simple ways to solve this, but the most common is potassium hydroxide. This will add potassium into the system, but hydroxide will also raise the pH, so it’s important to keep an eye on both the nutrient levels and the pH levels before adding any chemical to your system.
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Phosphorus
Phosphorus is responsible for healthy root growth, which is critical for aquaponic plants. The roots are constantly submerged, so an unhealthy root system will quickly rot in this environment.
Leafy greens have smaller root systems, so they don't need as much phosphorus. Fruiting crops have a more complex root system, so they need more phosphorus. Fish can handle large amounts of phosphorus in the water, although too much may cause an algae bloom.
phosphorous deficiencies are difficult to diagnose until they are severe. Dark green, red, or purple growth near the base of the plant is one unique sign of a deficiency. Other symptoms, like stunted growth, can mimic other problems. Correct a phosphorus deficiency with granulated phosphate, and apply it directly to the grow beds. Avoid supplementing plants that do not produce fruit.
Calcium
This is a difficult nutrient to manage, because calcium amendments almost always raise pH values. If your system could use a pH boost, then adding calcium may benefit the plants, but if your water is already alkaline, this may not be possible.
Calcium deficiencies can result in stunted and deformed plants. Calcium gives plants structure and strength, so a deficiency will result in lopsided and weak plant structures.
You can add calcium to your system with agricultural lime, which will also add raise magnesium. Calcium, magnesium, and sulfur are all dosely intertwined, and many treatments for deficiencies will affect all three nutrients.
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Lime will raise the pH, which is fine if your pH is low. However, if you don’t want to risk a pH fluctuation, you can apply calcium chloride with a foliar spray.