My pool store is a better deal

[CarlD]

DD: Usually, if a pool store sells them, then they sell FULL carboys (they are blue) and you pay a deposit on the container. But when you buy another, you give them the empty and don't pay the deposit again.
I've been cycling my 3 carboys for years now. It's also worth it to spend the $3-$6 for a carboy nozzle.

[BigDave]

There's also a wrench available for tightening / loosening the cap and nozzle. You may not need it, but I no longer have the hand strength I once did and it really helps me.

[CarlD]

Channel Lock makes a great wrench that's perfect for it. Harbor Freight sells an oil filter wrench that should be perfect.