I only have 3 birds. I have a waterer in the coop and in the yard, both one gallon. I treat the water with acv, 1 tbs per gallon. My question is this, how full should I be filling these waters? I figured if I filled them I'd not have to worry about filling them again for a while, they don't go through but a half gallon before I have to clean the sand out or scrub the algae growth, so I'm wasting the acv I'm putting in and it's not cheap. Should I get a smaller waterer or fill it less? I need to really clean it every 3-4 days. What are all of you doing? Also, if you ever have to medicate the water, and end up having to clean out the container before the water is gone, how can you ensure the chickens are getting their meds? Thanks for your thoughts.