I bought two 18" pots from WalMart the other day. They hold at least 10 Gal. of soil, here is what I'm looking at. As you look inside the pot, you can see 4 drain holes. They don't go through the bottom pan, it appears that there is a "water pan" attached to the pot (permanent). I filled the pot with water to see how it works and here is what happens, the water drains out until it reaches about 2 1/2 " from the bottom of the container, then it stops draining. Am trying to figure why it is made like this. The only reason I can come up with it being like that is to retain water at the bottom for the plant to use. Is that a good thing? Again, it appears to be a pot set inside a 2 1/2" deep water pan. Has anyone ever used one of these and if so, how did it work for you ? It seems like it would almost create a Tea like liquid after it filters down through the soil and keep the soil moist for root use....Any thoughts?