Yes. In my yard there is an area with quite a bit of slope/grade. I built my flood and drain box there. I thought it was going to be easy but it took me a quite a while. This was built in mid-march, so what you see is now 4 weeks growth.
I used part of a pallet to build my 40"X40" square 18" deep in ground box. I built it that deep thinking that i will use it for the final growth stage as well. But now I realize that just one tomato plant will take up the entire area. I lined it with water tight black plastic and built a Bell Siphon in one corner. I did not fill it with any medium. Just placed my transplants in one gallon containers (tomatoes) inside this box. The Blue plastic 30 gallon drum with opening cut out in the side (which is seen covered with black plastic) is located with its bottom about 3 feet below the bottom of the box. The top of the water level in drum is about a foot below the bottom of the box. The water
pump black hose goes from the drum to the box and siphon tube comes back to the drum. Later i added other plants to the same box, planted in various size net cups or gallon containers. Now I am using pretty much all the area of the box and have (about 20 good size plants and several lattices and herbs. Now the plants are ready to be moved out of this box into another area (which is still under construction). You can see all the plants: tomatoes, zuchini, okra, various squashes, cucumbers, bell peppers, herbs and some lattices. They are all doing pretty well.
You can see the set up in the pictures attached.
The slime cannot be seen in photo. It is just a thin brownish film on the tubing that is dunked in the drum. If i touch it i can feel that slimy feel between my fingers.