Indoor & outdoor hydroponics gardens of small, medium, and respectively larger dimensions usually require the use of some sort(s) of bench(es) or table(s) or other type(s) of support structure(s) to place the rhizobial region at a level above the nutrient fertilizer solution mixture reservoir to enable a gravity-fed supply-return system, unless supports are attached to the ceiling or columns or other types of structures, or if the reservoir is somehow sunk to a level below the flow-line.
Support benches are often built from various types of woods such as spruce or pine, or metals like steel or aluminium and can be bolted, welded, or screwed together, sometimes with the use of brackets and other types of hardware. Some of the simplest designs require nothing more than a supply of two-by fours and posts, some plywood, a bunch of screws and the use of a handsaw to erect. Tables or benches can be bought in kits, or assembled from plans.
As mentioned earlier, it is also possible to eliminate the inherent need for the aforementioned support structures by locating the nutrient fertilizer solution reservoir physically below the flow-line level of the growth-beds or trays by digging a hole in the ground or floor. In most indoor areas where it is not possible (or plausible) to dig a hole in the floor to accommodate the reservoir tank, an interesting technique that can be employed is to use the floor as the base of the growth tray(s) and to have the fertilizer nutrient solution mixture reservoir tank on the same level, but to then have a nutrient return pump situated in a division of the growth tray in addition to the input pump. These two pumps can work sequentially to feed the plants cyclically on a timed schedule. The nutrient solution return pump can be sequestered into it's own secondary section of the growth tray, while keeping the growth substrate media in the other by using a semi-permeable filter material of correct porosity.