To build basins, you first need to research Hydroponics at the research bench.
A hydroponics basin (100 steel + 1 Component) provides a highly fertile medium for growing food quickly. With the use of sun lamps, it can also be used for growing crops indoors. Hydroponics basins provide much more fertile environment than soil and any crops planted in them will grow much more quickly. Still, they do have some disadvantages. The first is that they need of power to operate, without which the crops planted in the basin will rapidly die. Thus, solar flares will kill all hydroponics crops, though pawns can be ordered to harvest partially-grown crops before they wither, to prevent a total loss. Breakdowns and conduit explosions are also a concern, though crops can be saved if power is restored quickly enough. The other disadvantage is the limited selection of crops that can be grown hydroponically. Currently, only potatoes, rice, strawberries, cotton, hops, smokeleaf, psychoid, and healroot can be grown in hydroponics basins.
The basin provides only soil fertility. All other plant growth conditions must still be met. Plants require light during the day and need a temperature within their comfortable range. Sun lamps are required if you're growing indoors as they are the only artificial lighting source that provides enough lighting for plant growth. Standing lamps only provide 50% lighting, not enough for growth. Plants also need heat when it's cold and cooling when it's too hot. Just outside of their comfortable range, plants will not grow at 100%. Too far outside of that range, they will die.
It is possible to fit 24 hydroponics basins inside the "brightly lit" area of a sun lamp with the following configuration:
This Setup will use 4580W at day and 1680W at night, a Solar generator produces 1700W and a Geothermal generator 3600W, so 2-4 Solar Generators (and a few Battery ) or one Geothermal generator are needed to power it.
If there is a roof over the hydroponics area, it may be wise to use the four empty tiles for roof support columns. This is not necessary if there are supports immediately outside the sun lamp's radius.
How to prevent short circuits
If it is raining on the sunlamp it WILL short circuit and cause fires. To prevent this, simply build a wall and build some roofs connected to the wall over the sun lamp.
Roof under construction. Build walls first, then sell unnecessary walls and last build the lamp ▩ ▩ ▩ ▩ ◉ ▩ ▢ ▢ ▢ ▩ ▩ ▩
Please note that a recent change in how roofing is created has made it so that there is a hole in the middle. The fix is to place the lamp on a square the walls previously stood on.
Roof done, the lamp is protected & the unnecessary walls has been sold. (the lamp is moved to be under the roof) ◉ ▢ ▩ ▢ ▢ ▢