My friend has been using those cat litter square pails that come with some brands of cat litter. Some of them are about the same size as the waterfarm buckets without the inside bucket.
He has had problems with water log on the bottom half of the bucket. What he did was to put a 1/4" hardware cloth in at about the top 1/3 of the bucket, then added some coco fibers, some lava rock, more fibers, potting soil mix he uses. He put a stone in the bottom with air pump. He waters as he usually would water his soil grow leaving the water in the bottom for the roots to grow into. About 3 or 4" from the bottom, he put a drain hole so the water would not get any deeper.
I guess in some ways, it is the same system. I am going to show this to him and see what he thinks. I don't think he thought about the plain water in the bottom. He just let his nutrients build up until they reached the drain hole. He waters every so often with ferts and other wise, plain water, just like he does with soil.
I didn't know that there was a name for it!