The ideal conductivity levels of a plant is given as a scale. The feeding level should increase from the minimum to the maximum following the basic stages of growth, as detailed below.

PROPAGATION.

This is the development of a seedling or cutting into a plant by establishing a root system within a Rockwool block or inert rooting medium, before it is put into the system.

VEGETATIVE GROWTH.

Once in the system, the plant will continue to grow roots and develop shoots etc, until the lighting period is reduced.

PRE-FRUIT/FLOWERING.

When the lighting is reduced a plant will quickly realise and go into a period, lasting approximately 2 or 3 weeks, of concentrated root and shoot growth, whilst initially forming buds.

FRUIT/FLOWERING.

Following the pre-fruit/flowering stage a plant will then transfer its energies into the production of the fruit/flowers.

FINAL SWELLING-UP.

In the last week of the plants growth, the absorption of nutrients from the solution will slow down. The plant will also start disposing of excess nutrients.
The conductivity level of the nutrient solution should ideally rise gradually until the end of the pre-fruit/ flowering stage (2/3 weeks after the lighting has been reduced), when it should reach its maximum. This level should then be maintained until a week or two before harvesting, when it can be lowered and/or the system flushed.

Below is an example of the ideal feeding pattern for a plant with a CF range of 16 — 24, grown over three months.

And for a plant grown over four months.