Plants need to have fresh nutrients available for healthy growth. Ensuring regular reservoir changes every week is essential. pH and electro conductivity should be checked while mixing the nutrient solution. While the electro conductivity reading will help determine the amount of dissolved nutrients, the pH reading will help in maintaining pH values at levels that will enable plants to absorb the nutrients.
Leaching or rinsing should be carried out one week prior to harvest. This can be done using regular tap water through the system to wash out excess salts that remain in the growing medium.
Keeping a gardening journal will help in avoiding mistakes and establish pointers to the right course of action. Making journal entries regularly will, in the course of time, help build up a veritable treasure trove of valuable information on various aspects of nutrients, pH, EC etc.