Hydro and soil in one room?

What would happen if I started growing plants in my hydro kit but also had some additional soil plants next to them? They would all be started inside and would never be outside.

tahts what i got goin on, there all in flowering so i dont think it matters too much

As long as the soil is sterile and bug free, you should not have a problem. I would not dig soil from your yard to bring inside. You could bring spider mites into your grow.