I picked up this sand filter last season after my included Intex cartridge filter went bad. It is working fine, but was missing the bottom cap when I got it. I was able to get it sealed up pretty well, but it still leaks a little and I would like to find the part. The last picture shows the cap I am talking about. I tried to find one at the hardware store, but the connector is flat on the sides instead of being completely round. The tank is 21" diameter.
Here are the pics, I uploaded to my Dropbox as they were too small when I scaled them for the site:
In case the pics are hard to read, the motor is a GE 5KH36JN3032 and the valve is a Praher TM-12-L