I would suggest using them as an addition. If you are not familiar with hydroponics, it is a method of growing plants using nutrient solutions. It works by having the roots in a solution and the plant uses the water to transport nutrients into the root system. There are two basic types of hydroponic systems: a hanging basket system and a tray system. In a tray system, the roots are grown in a tray of nutrient solution and they are submerged in the solution. The roots grow down into the solution and the solution is constantly being replaced. This is a slow growing method because the roots are growing into the nutrient solution rather than pushing through it. In a hanging basket system, the roots grow out of the nutrient solution.