Light

An important consideration before setting up a hydroponic system is the effect that light will have on the nutrient solution. It would be easy to expand the system already described so that instead of growing plants in a saucer, they were grown in a larger container filled with water and nutrients while an aquarium pump could be used to provide the oxygen.

However if light is able to reach the nutrient mix, either because it is in a transparent container or if the top of the container is uncovered, then algae will soon start growing. It grows rapidly on the inside walls of the container and on the roots of the plant. This is undesirable as the algae is an unwanted organic substance which will upset your carefully balanced nutrient mixture. This is why the nutrient mixture used in hydroponic systems should not be exposed to the light. Light proof covers and materials are used in most systems.

 

Although plants grown hydroponically will not be competing for nutrients, they may still have to compete for light. Space your plants making an allowance for the size they will reach at maturity. Light is the main source of energy for plants so optimum light conditions will play an important part in achieving optimum growth. A greenhouse enables you to provide your plants with plenty of light all year round without having to subject them to winter frosts or any of the other unfavourable conditions they are liable to be exposed to outdoors.