My girlfriend has an older Sundance spa that has developed a leak that drained the tub most of the way. We both know nothing...zero...nada...about tubs. I'm not sure what model this is...the control panel says "Sentry 605". The leak is coming from a round, blue part in the lower left area inside the access doors. I have a couple of pics I'll attempt to post.

My question...what is this part? Is this a repair that a reasonably skilled home mechanic can tackle?

Thanks very much in abvance!

Back end of a pump. Probably a pipe union that has a o-ring that blew. Careful- no wrenches on these fittings.