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contentedPilgrim's Achievements


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  1. I appreciate your reply. My understanding is that ozone oxidizes chloramines and this creates more FC. Does the FC then off-gas? Or is the chlorine level reduced some other way? If indeed I can work it so that there isn't residual FC, I am open to rethink. When the ozone oxidizes the chloramines, what are the resulting compounds?
  2. Definitely a thinker and certainly don't skimp in my efforts to understand how something works scientifically. From what I can tell, the ozone plus UV should allow me to reduce MPS usage significantly. As far as the 1 in a million for a flesh eating bacteria - way less than that - especially for a private hot-tub. The dangers of chloroform inhalation and absorption (by-products of chlorine usage) are higher on my list of things to avoid. Hence my plan to only use chlorine as a shock once a week and not have residual chlorine in my spa while soaking. The Nature2 + MPS + ozone and UV will take care of sanitation for me.
  3. Thanks for the reply. I completed my purchase and have spent the last 3 days doing research and read through Chem Geek and Nitro's posts. I've adjusted my initially posted routine as below. I'm still trying to figure out how the ozonator will impact how much MPS I need to add (half?). I am also unsure on borates due to health concerns (banned in the EU). 370 Gallon Sundance Spa with built In ozonator & UV Nature2 Mineral Stick – changed every 4 months Initial Fill: This should give me a balanced tub with a Saturation Index of -0.04 (without borates) Calcium Hardness - 130 ppm (mine is very low and I have to add calcium) pH – 7.6 (stabilized with jets) Total Alkalinity - 80 ppm (my well water is low and I add baking soda) Borates (undecided) - 50 ppm = 13.5 oz of Boric Acid / 370 gal Dichlor – 10 ppm FC (9 ppm CYA) - 1.7 tbsp / 370 gallons (Nature2 says 1.5 tbsp / 250 gallons which is 13 ppm FC) The first week: (to get CYA to between 20-30 Dichlor - 7 ppm FC (6.3 ppm CYA) – 3.5 tsp / 370 gallons per person hour - 3 doses adds 19 ppm CYA for a total of 28 ppm Maintenance: MPS - 7 ppm CC registered - 2.5 tbsp / 370 gallons per person hour - OR HALF because of ozonator? Bleach - (weekly or bi-weekly) – 4 ppm - 2.4 oz / 370 gallons (7.5% bleach) When Needed Bleach - shock – 10 ppm? - 7.7 oz / 370 gallons (7.5% bleach) - w/ added acid first
  4. I developed the below sanitizing routine over the past 16 years with my Marquis 450 gallon spa and it worked well. I am purchasing a new Sundance 980 Lisbon (370 gallon) and am planning to use the same routine (scaled down by 20% for less water) but want to corroborate with others the science behind what I've been doing. Aside from water health, my goal is to have the minimum amount of chlorine in my water. My routine: Nature 2 plus changed every 4 months Initial Fill Only: 2 tsp of sodium dichlor (3ppm) - wait an hour then add 1/2 cup of MPS Shock weekly with MPS (3/8 cup = 3oz) Add 2 tbsp of MPS mid week if heavy use. Ozonator This is my understanding of how it works and what I'd like clarification on: With the initial water fill, the chlorine binds to contaminants and is turned into chloramines. The weekly MPS shock pulls the contaminants from the chloramines and frees up the chlorine to be active again - but in a minimal amount. The Nature 2 does the rest of the job of sanitizing along with the Ozonator. The new Sundance will also have UV. As I understand it, this method is difficult to detect the level of chlorine (free or combined), so I'm going by the seat of my pants - and water clarity. I also don't understand what the MPS turns into after added to the water and what accumulates over time because of it. Other tidbits that probably have something to do with the balance, and I'm including just to make sure I've given all relevant info: My water is naturally soft (10 ppm Calcium) and I have to add a fair degree of Calcium at startup. My water was frequently basic and I had to add a small amount (1 tbsp) of dry acid to balance. Alkalinity was always low. If I tried to get above 60 ppm (using baking soda), the tub would get too basic. I chose keeping the pH balanced and occasionally added baking soda to increase alkalinity to 60 ppm. Thanks in advance for any insights.
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