5 gallon buckets made into "earth boxes," feeds from below.
Add pure coco. Feed should go Strong at first and gradually down. You can monocrop in them too. 1 gallon of nutrient water can last between a 4 days and a week. Since it feeds from below, the top layer of coir never gets wet. No gnat problem. Humidity is not a problem either since the water us trapped inside the bucket.
You gotta make a gallon of water for each 5 gallon bucket... and pour each gallon into the downspout. This could be annoying but it's worth it imo.
... Lost last 2 crops to mold from the amount of moisture it puts into the air from evaporation. I am hobbyist, and can't afford to add AC or will be frying more circuits.