So finally I am going to finish the decontamination process and get my ht up and running again. One of the steps in the decontamination process is to overfill and balance...does this mean cya as well or just the basics, FC, CA, PF and TA? Can I do this step generally in the same day that I drain and refill for use?
Also, I know we need another ht cover, but we are just plain tapped out on funds right now. I had the cover on during that last bought of rain and my nice dry and empty ht was once again filled with rain water, so off to empty it again before I start the refill. Will I run into this problem with a new ht cover as well or is this just because it's old and past it's prime?
Thanks..off to drain the rain

B

As for CYA, you've got two choices. You can treat it like one would a pool and add 30 ppm of pure CYA to the water or you can just use Dichlor as your chlorine source until you build up around 30 ppm CYA, so using Dichlor until you've cumulatively added 33 ppm FC and thereafter switch to bleach (possibly adding one day's worth of Dichlor once a month to keep up the CYA level that usually drops around 5 ppm per month in a hot spa). Either approach is fine. The initial CYA will technically give you a more consistent active chlorine level almost immediately, but that's not a big deal. I assume you are following the Using Chlorine in a Spa instructions.

The hot tub cover should not leak so a tub should not fill with rain water. A new cover shouldn't have that problem.