A couple more "for what its worth" comments to add to GeoB.

I use what was a brand new plastic gasoline jug (5 gal I think). I use a solid rubber stopper from my homebrew stash. I put the in/out tubes in hole drilled in the top of the jug and siliconed in place.

The long tube in the jug can be just short of the bottom to allow some settling to remain.

A question: Not that I was real concerned, it's been in use for a few years, but should I have been concerned with the use of such a "gasoline" container? Obviously it was never used for such a liquid. At the time, it was cheaper than a "water" jug.