I have a 310 gal hot tub made by (Watkins) Tiger River Sumatran. This hot tub has ozone and Silver Ion Purifier. The last five years I have maintain this tub per manufacture guide lines and had no problems except a musty smell whin I would first open the cover and a yellow stain on the inside of the cover above the bubbles from the ozone even after changing the water. I also had a very high acid demand and the same smell.
These are the numbers Watkins ask for.
Cl 3 to 5 ppm
PH 7.4 to 7.6
TA 125 to 150
CH 150 to 200
Sanitizer Sodium Dichlor
I also would shock once a week per dealer instructions
change water at 3 months
I started useing bleach about 4 weeks ago and this is how i set it up ( this is very close to what my pool is)
replaced with fresh water and did not change the Silver Ion ( just left the old one in) still running the Ozone.
CL 3 to 5 PPM
CH i didnt bother but I probably should
Santizer 6% bleach
added borax to about 30
added CYA to 20
This is the difference in the tub I have found. I add less acid per week (about 1 tsp for 3 days)
add less CL then before ( about 4 ounce three days)
I have not shocked in 4 weeks. (no CC)
the yellow stain has disappeared from the bottom of the cover
the musty smell is gone.
the water is clean and fresh and stays that way. I really like the feel of the water it is very deferent then before
Question to the chem geeks Should I run sanitzer higher at times to prevent hot tub itch?? ( i have not got it yet)
This is what I think my problems with the musty smell were. Recommended TA was to high. If anybody knows why they recommend so high I would like to know. Also the weekly shocking i think it had a lot to do with it. The cover stain i think would have come from the same. Also the same old problem of to much CYA
I have heard a lot of people ask about that musty oder from the hot tub but the only ansers i had heard was ck the ph. i am posting this so if anybody is having this problem it could help.