Free 5gal. cloche'

A friend of mine delivers 5 gallon bottles of water for office coolers. He told me that they just throw out the cracked plastic bottles, and usually have at least 2 or 3 per route per day. Well I went and asked for them, and they gave me a dozen, I brought them home and used my cutting wheel attachment on my Dremel to cut the bottoms off, some still had good bottoms so I'm going to use them as flowerpot saucers, these things are great, once the bottoms are cut off they just stack up, and they fit perfectly over some of my larger pots too. My husband said that they could be weighted easily, just by tyeing a brick to a stick with a length of twine and then setting the stick across the filler/vent hole and letting the brick dangle inside, the brick would also absorb heat during the day and slowly release it at night.