Whirlpool Junk

I had the shock of my life when I turned the jets on in the whirlpool bathtub junk shot out.

I get the same thing in my spa when I don't used if for quite awhile. I drain it, refill and drain again. It does take at least two cycles to get most of it out, then the filters will clear the rest. It's deposits that build up in the pipes when the tub is not used. Not sure what the chemical makeup is, but it's just ugly, not harmful.

If you dig out the user's manual or try to find it on-line, they dictate (typcially) monthly maintenance that MUST be done on the things to keep them fresh. When you fill up the tub, even if you don't turn the pump on, the lines will contain some water. This is stagnent, and will grow all sorts of nasties. The only time those lines were dry is when they were first made.

I opted for an air jet tub rather than a whirlpool. It isn't as vigorous as a whirlpool, but it can be close depending on the design. All of the passages drain on this instead of holding stagnet water, it doesn't hurt to turn it on dry, and it blow dries the passageways 15-minutes after your finish. You still need to let it soak in a cleaner once in awhile, but nowhere near as often as with a whirlpool.

This is from Jacuzzi's website...they want it cleaned at least twice a month..

Purging the Whirlpool System​

NOTE: THE WHIRLPOOL SYSTEM SHOULD BE PURGED AT​

LEAST TWICE A MONTH​

To remove accumulations of bath residue from the whirlpool

system, it is recommended that a whirlpool bath be purged at least
twice a month. For best results, however, we recommend that you
purge your whirlpool bath after each use using, Systems Cleanâ„¢, our
exclusive two-part plumbing system cleaner made specifically for
whirlpool baths.
Systems Cleanâ„¢ is available through an authorized Jacuzzi
Whirlpool Bath Distributor or by calling us direct at 1-800-288-4002.​

Jacuzzi has a two chemical cleaning procedure. You put part one in the hot water after you are finished...run the thing for a prescribed amount of time, then drain it and replace with cold water, add chemical 2, and repeat. When you are done, you've cleaned the pipes, or purged them of crud. You aren't really emptying them...

WIth my air tub, it isn't anywhere near as messy, since there is no retained water in the passagways (that is the main reason I bought it vs a whirlpool), so it is much less of a factor.

Both of them say you can add a little bleach to help kill things, and I've done that. The rest I've done is just keep the surface clean, but I should probably get some of their cleaner, too.