We use one of those orange cooler containers, put a bag of crushed ice into it every second or third day. All depends on what else goes into it at what temp. Once we get the ice melt going, we don't add much extra water. Ours is always vaguely lemon gatoraide~ish as we dump packets of electrolytes in it. We still have a food cooler and a drink cooler, mostly for beer and powerade and juices.
Edited to add: we have three to five people using it, hence the faster ice melt/water use.
Some sunshine, some dust, a little paint and a tutu. Yeah.