Hot tub vs spa: what's the diff?

You probably already know that "hot tub"� and "spa"� are two words that mean the same thing. Synonyms in other words. (Or, depending on what you do in them, sinonyms.) Hot tubs/spas come in two variations: self-contained and non self-contained. The self-contained version or portable spa, the electrical, filtration and heating system are inside the unit's cabinet. If you want your self-contained to look built in you can install it above a surrounding deck. Of course, it goes without saying that these self-contained units can be moved and re-installed elsewhere. That's why they are called portable. Non self-contained hot tubs, on the other hand, are installed in-ground and are meant to stay there. Often the electrical, filtration and heating systems of these spas are located away from the spa as part of a spa-pool complex, known informally as a spool.(Not really.)