I've got a couple of those, one outside under the downspout, and another in the basement for reserve and winter use. I have them for watering my bonsai and houseplants, which don't do well with our hard water.

If I'm not careful about making sure the water is settled before filling the one in the basement, it gets skanky. I found that I can fix that by putting a submersible aquarium pump in it. Now the one in my basement is sparkly clean.