2) Then, Nutrients and water is added to the reservoir. 3) Keep checking the pH of the liquid in the reservoir. It must be between 5.5 to 6.5. Use a pH meter to know the pH of the liquid. If it is above or below, then plants won’t grow properly. In this situation, use. Oct 14, 2006 · In DWC the roots can fill the entire volume of the container, while in soil the roots must displace dirt as they grow. The difference in yield you describe is based totally on this distinction. For example, try a dwc bucket with organic nutrients and you should get similair results as you got using GH nutes..DWC is one of the hydroponic systems that requires the.