The VG-1 is our smallest system, only one stack, automatic watering, for a hands off operation. The stack of 4 or 5 insulated pots sits on top of the fertilizer tank, so the unit is self contained and re-circulating.
Many kinds of crops can be grown in this type of system, you can see many examples of what can be grown here, although the crops shown are in commercial systems, they can be grown in the same manner in the re-circulating units.
If your ambitions are a little higher, you can try our larger unit, the VG-2, which is basically the same but has two stacks instead of one, the fertilizer tank is larger to accomodate the doubling of the stacks, but the operation is basically the same. I only takes twice the space and can grown twice as many plants in each unit.