I have a hot tub, about 6 months old, and I noticed it leaking at the shaft seal on the main pump. It's not a big leak, let's say about a quarter to half cup of water during a typical hot tub session. There's white residue around the shaft, and white residue on the floor where it has been dripping. My previous hot tub went about 10 years before having any pump problems, so I'm surprised this has happened so soon.
I'm wondering if there's anything I've done that could have caused this? I've tried to maintain all of the chemicals within limits. I do use chlorine as my sanitizer, and I find it does take a fair amount to keep the recommended 3-5ppm residual level (about a tablespoon, each time I use the tub).