An effective way to grow marijuana is using an open circuit hydroponic system. It's ideal for larger crops but is probably not useful for hobby or small-time growers. It gives better results and helps the plants to grow quickly. Advantages and Disadvantages of an Open Circuit Hydroponic System It can be expensive because it uses a lot of fertilizer and can have a lot of waste the needs to be removed. It uses a fiber substrate such as coconut fibers or rock wool. They can hold a lot of ...