Growing under HID lighting systems has turned into a science, and most growers understand specifically how much of everything is needed and when. When switching to an LED light setup, many individuals make the mistake of keeping everything the same, which ruins their crops. Usually hydroponics systems are perfect for an LED light switch, since they offer additional control and visibility of what is happening with the plant. Even if an error is made, hydroponics setups will show the weakening and following regeneration much more clearly than standard soil setups do. Many people looking to save money through LED lights will usually feed their soil setups too much water and nutrients, and get poor results or kill the plant along the way.
The change in heat is the primary reason this happens. In HID setups an enormous amount of heat is generated which the traditional nutrient and water amounts have accounted for, but LED grow lights produce almost no heat at all. The plant, soil, nutrients and water all react differently to heat, and amounts of everything must be adjusted to suit the new environment. Less is a lot more in most LED setups. Besides chemical reactions brought on by these lights, the heat from HID grow lights evaporates the majority of the water and nutrients added into the soil generally. LED bulbs are best tried out over hydroponics systems because the only real variable is nutrient intake and not quantities of water. Including less nutrients in each type of setup will reduce 'nutrient burn' that triggers discoloration of the leaves.
Experimentation is the key to both types of setups for the best. Even variables like the environment's dampness and height of the lamp to the plant play a huge role, so playing with these helps a whole lot. It is crucial to keep a journal of the changes that are made for the plant and the reactions of the plant to those changes daily to determine the best balance, but LED systems often produce higher quality plants than HID setups do when used correctly.