You are on a much larger scale than I have
experience with but I started using the
bucket method from
jack Spirko at the survival podcast. It's 5 buckets with some holes that results in sprouts rather than grasses (I've read this is better as they have not reached the photosynthesis stage and maintain a higher nutrient content)
Simple quick and a small foot print.
Later I moved to using 8
concrete trays one on the bottom set 2 ft off the ground with no holes in the bottom but a drain spigot in the center the other seven stacked on top with 1x1
wood sitting across to elevate them to allow growing space have drainage holes drilled along the bottom. I use
apple cider vinegar in my initial soak just a cap full per 5 gallons. It's supposed to keep mold at bay but I never had an issue with mold before I used it. Once they are stacked I fill the bottom drainage tray that is nested in the spigot tray with
water to soak the seed for 24 hours then drain that and fill the bottom tray with new seed and pour the water I drained over the top tray so on and so forth until I run out of trays. They are usually ready in 5-7 days and the rotation continues.
If I were to improve on that system I would make a sturdy frame that the trays slid in and out of and add a pump to sump bucket below the soaking tray with a timer to flood the seed trays at the top couple of hours and allow it to trickle down to the reservoir again.
That being said a stack of five gallon buckets with holes in them doused once or twice a day with rainwater works pretty well!
Good luck
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