When do I have to water the plants?

Temperature is the key to the amount of water you need to give your plants. HPS lamps give off more heat, which causes plants to use more water. LED lamps give off less heat, so the plants need less water.

A good rule of thumb is to determine the weight of the pots by lifting them. A heavy pot is full of water and a light pot is dry. Wilting leaves are also an indication of a plant in need of water.