Maximum Yield USA December 2016 | Page 127

Sufficient space allows for more foliage, which puts greater demand on the plants to produce larger roots. Once the plant is ready for the bloom phase of growth, and the roots are fully developed, some of this foliage can be pruned away. As crop yield and space utilized go handin-hand with the size of the root system for each plant, the access to an abundance of photosynthetically active radiation (PAR) provided is also very important. Available light relates to the watering system in that the set-up of the system allows for sufficient spacing. Because it can be easier to provide more growing area with drip than with ebb and flow, drip systems have an edge in this category. Efficiency – Nutrients & Energy Electricity use is usually a big consideration for hydroponic growers. The energy used to provide light energy for the plants is by far the greatest factor, while the energy used for watering is far less. In regards to this aspect, the only extra energy used by an ebb and flow system is the water that is pumped up to the tray that fills the spaces between the pots, and the amount of cycles the pump needs to run. If the drip system provides adequate distribution and even water to each plant, the energy for watering the pots is equal for each system. Only the energy for watering the spaces and the number of cycles required is different. Usually, a 40-50W pump is plenty enough power for about 10 seven-gallon plants. At $0.22 per kilowatt hour and a 40-minute run time every day (more than needed in many situations), this would amount to around $0.22 per month for drip and $0.66 for ebb and flow. This is not significant. The fact that most ebb and flow systems require more cycles and an aeration pump running to keep the solution from becoming anaerobic and toxic will add a small amount to your electrical and set-up costs. Maximum Yield USA  |  December 2016 125