PVC parts and glue may be needed to fix the leak. Common hot tub PVC plastic parts include elbows, tees, reducers, hose or pipe and unions.
Manifolds direct the water from a larger hose or pipe to several smaller hoses that usually connect to jets. Most hot tub manufacturers use a manifold plumbing system in order to assure even pressure at every jet. Basically the water manifold is a water splitter and the air manifold is an air splitter.
A spa that is left empty in the freezing winter may have a cracked manifold or two. Those can usually be found easily because water comes gushing out of them as soon as the hot tub is refilled after the season. This is why it is important to properly winterize the spa or just leaving it full over the winter, even if the temperature is turned down. Leaving the hot tub filled also allows the freeze protect systems in the controls to work.
When glueing parts together, it is first important to dry-fit them to assure they will all fit in the right place. Then apply glue in a circular motion around and around both joints to be connected. This also builds up heat and allows the two parts to bond better. Use a fast drying PVC glue ideal for hot tub use.
Some hot tub techs like using a primer first to assure a better bond. This is a good practise, but many times just gluing 2 brand new, dry joints is also adequate when using a good PVC glue. Never hurts to prime and it does pre-treat the connection for a sure fit.
Once the PVC glue has cured (usually best to leave it for 24 hours or so even if dry in 5-10 minutes as is the case with the fast drying WeldOn type of glue), then refill the spa and check the connection as well as for any other leaks.
As long as the spa is not of the fully foamed type, getting at and repairing leaks is a straightforward process most of the time.
Get your plumbing parts online at the Hot Tub Outpost.