I bet the darn squirrels would love to get into it, too. and the coons - we used to build covers out of hardware cloth & wood to put over our garbage cans so the coons wouldn't take off the lids, so there's a solution right there!Sure it's possible with 150 chickens! I have just under 100 (granted a few are chicks). Right now I have a 5 gallon bucket in the shade near each coop, but I think you might have an easier time with a larger container. I have heard of some people using trash cans or barrels, but I wouldn't recommend it because they are too deep to mix everything properly. I get feed tubs from my step dad (he raises cattle) that might be perfect for you. I store unopened bags of feed in them, and they hold 2 50-lb bags with room to spare. They are much shorter than barrels and it would be much easier to mix in them. I can probably get a couple for you if you're interested. They look like this, just a little shorter and wider:
I use a single container rather than nesting 2 together (some people use 2, with the interior one having drainage holes). I use my regular feed and occasionally add in some BOSS or other whole grains if I have them on hand, but it isn't necessary. I recommend letting the first batch ferment at least 2 days to get it going good, but you still need to stir it a couple of times daily. I don't use as much water as ssterling, because I don't drain my FF. I tried both ways, and this is much easier and less time consuming with so many birds (AND it ferments just as well). I mix mine until soaks up all the water and has the consistency that reminds me of a slightly thin cornbread mix, then I top it off with a couple of inches of water (because it will soak up more overnight) and stir one more time. I mix everything once before I feed, because the mother will start to grow and gather on top of the feed (sort of grayish colored) and all the good ferment liquid is on the bottom. I scoop out without draining and feed. It does have a little liquid, but my birds LOVE it like that. They haven't been drinking nearly as much water either. After I feed, I add in more dry feed and water, stir, and it is ready again the next day.
I have a VERY important suggestion if your ferment buckets will be somewhere your birds can get to them. It is important for the FF to get air (thus ssterling using a towel to cover), but it also needs to be protected from debris or animals getting to it. I use the bucket top and don't press it on, and I still get enough air exchange. I made the mistake of leaving the lip of my lid too loose on the front side (the other side backs up to the fence and the birds can't get there) this weekend. My geese, who love FF and who are very smart, took the lid off while we were not home. I came home to find a near-lifeless silkie who was submerged up to his head and hypothermic. It took me nearly 2 hours to revive him. My story had a happy ending, but please make sure you take steps to prevent this. The birds will try to get in the container once they figure out what's in it. It is nearly impossible for them to get out without assistance. This stuff is like quicksand.
It took about a week for me to start seeing a big decrease in the amount of feed I was using. Keep in mind that you are going to start with a larger amount of feed than you will feed in one day, because you need to have some left over to ferment the next day's feed.
My birds know when it's close to feeding time. They all gradually congregate at the buckets.
I'm going to try it I think. I only have 23 chickens so it won't be overwhelming.
OK Mike -- we're on! see you there! and do keep me posted on the cotton patch; I'm very interested!
I still don't understand. Fermented grapes gets me tipsy 
so what does fermentation do for chickens? 
