THE OPERATING PRINCIPLE
The dosing pump is made of two parts:
THE HYDRAULIC MOTOR
The Motor piston moves thanks to the water pressure. A system of valves allows the movement to be reversed. Each piston cycle corresponds to a fixed volume of water flowing through the pump. (motor volume) The motor speed will increase proportionally to the drains water flow.
The dosing pump is said to be VOLUMETRIC.
THE DOSING PART
The Dosing piston driven by the motor continuously injects a fixed volume of chemical (doser body volume). For each volume of water flowing through the motor (1 cycle), the dosing piston will inject the corresponding volume of chemical. Consequently this operating principle guarantees a constant dosage, independent of water flow or pressure variations.
The chemical injection is PROPORTIONAL to the water flow.
The Fertigation by Water
A and B injection installation
Keep nutrients soluble and available:
Nutrients are commonly separated into at least two parts, A and B, to keep specific ions, sulfates and calcium, apart.
If these two ions are not kept apart, they will combine (precipitate out) into an insoluble form.
If this happens, the ions are no longer available to the plants. Some micro-nutrients also readily precipitate out.
This is generally prevented by adding micronutrients as chelates.
Nutrient supply in soil-less growing:
In hydroponics and soil-less growing, nutrients are primarily provided in the water supplied to the plant. That is, a nutrient-rich solution directly provides plant roots with the essential nutrients they need.