New Here...Have Green Clear Water

[Watermom]

I have never seen a kit with a tube that goes to 15. Have you used your kit yet? If not, I'd consider taking it back and finding the K-2006. A MUCH better kit and way more user friendly. Maybe try a different place to order it. Take a look at this thread.

http://www.poolforum.com/pf2/showthread.php?t=10006

Can't help with the hot tub question. But, I *think* in a hot tub, you need to use bromine because of the extremely high water temps.