There are a few reasons one might want to transplant from DWC to soil. This shortlist includes:
- Wanting to plant outdoors
- Heat issues preventing DWC from being feasible
- Slow down growth for a mother plant
A plant in DWC is used to having much more nutrient and water absorption capabilites than it will have in soil, so there are some steps you can take to decrease stress and increase your likelihood of success.
Spread out the DWC roots

The roots should be spread out as much as possible. If it is feasible to do so spread the roots into two parts that you can make an underground “T” with.
Which Soil to Use when Transplanting from DWC to Soil
A major key to successfully transplanting from DWC to soil is using a soil that drains well. This will prevent the mass of DWC roots from getting root rot. My choice is ProMix HP. The HP stand for high porosity. The large amount of perlite in this formulation allows the soil to drain extremely well, preventing the roots from staying wet for too long after watering, which can lead to rot.
Re-plant at Sun-Down

Regardless of if you are transplanting outside or inside, you should do so at the end of a light cycle. Light causes evaporation which can stress a plant that is getting used to a new environment. Do your transplanting at sun-down or at the end of a light cycle for indoor growers.
Defoliate the Plant after DWC to Soil Transplant

Remove all large fan leaves from the plant (seen on the left in this picture above). This will decrease the transpiration rate as the plants will have fewer leaves through which they “lose” water. Since the root system does will not have the same access to water in soil as in DWC defoliation will keep the plant from wilting and help it survive.
Water the Plant Immediately

It is important to give water immediately after transplanting. After the first watering follow regular protocol for soil. That is you need to water according to how quickly the soil is drying out. If it is sunny/dry you may need to water daily or multiple times a day. If it is cloudy and wet you will not need to water until the soil drys out. The important thing is to let the soil dry out before re-watering or you are at a high risk of root rot. Especially with the way DWC roots will clump together when transplanted into soil.

Within a week or so you will know if the plant made it or not. No wilting means success. This plant is still showing slight signs of nutrient deficiency (slightly yellow leaves) due to the decreased ability to uptake nutrients in the new environment. This will go away within a few weeks as the roots spread out and are able to uptake more nutrients.