Doggier

Simplest...three step bromine (sodium bromide, oxidizer (my preference sodium hypochlorite), and bromine tabs in a floater to maintain. Ozone can be an effective adjunct oxidizer to activate the bromide. Most effective...in a word....chlorine (more work than three step bromine but not that bad if the spa is regularly used. Ozone is less efficient than with bromine since it tends to destroy chlorine and vice versa. Silver/MPS (N2 and Silspa)...can work but often succumbs to problems and does require weekly shocking with chlorine. Biguanide/peroxide...only as a last resort for those that have a TRUE halogen sensitivity (as determined by a doctor). The above 4 are the ONLY EPA approved spa sanitizers, btw. Thanks for your input. I initially used your simplest method but experienced sensitivity to bromine. I like the look of the choline method. Other than maintaining alkalinity, what else is required with this method? I am lucky enough to live in an area where water hardness is not an issue. Am I correct in assuming that you feel no shock is needed?

if that is true then why is soaking in a mixture of silver nitrate, zinc sulfate, chlorine and potassium monopersulfate more minimalistic than just soaking in chlorine? Given your status as spa guru I imagine you could answer this question better than I but... number of chemicals does not equal total chemical exposure. This is a quotient of chemical X volume X time with a complex consideration for interactions. Also important to consider is that not all chemicals are created equal. ie ozone is far more hazardous by volume than Chlorine and choline more hazardous by volume than monopersulphate ®. Silver Nitrate and Zinc Sulfate are low hazard as topical agents. The user and use patterns are also important considerations. The simple answer is that if one can introduce a broader spectrum of chemicals, with lower total quantities of overall chemical intervention, and yield fewer negative effects, this would be IMHO more minimalistic. All that said, I am always looking for constructive input. What do you feel is the simplest and most effective method of safe spa maintenance?

Thanks, I'll keep looking. BTW, what system do you use now? I'm a minimalist and like to soak in the least possible amount of chemical while still enjoying a safe experience.

Thanks for the info. I have a couple questions: - How does chlorine activate the N2? My understanding was that activation was a chemical function related to electrolysis that occurs when the cartridge is submerged in water. I do understand the positive oxidation implications of the interaction of N2 and MPS but I have not seen water chemistry documentation supporting the need for activation via chlorine. Any info is appreciated. - What do you feel is the most cost effective way to purchase N2? I'm currently looking for a cartridge that gives the best value (lowest price per gram). My intent is purchase the largest cartridge possible. To break open that cartridge and use the contents to fill the cartridge for my spa. Maybe there is one that is intended for a pool that is much better value. Any ideas? Thanks

I'm using the Nature 2 system called SunPurity that is packaged specifically for Sundance Spas. Now that I've sorted out the best way to use the product I am very happy with it. Here is my issue. The dealer sells the cartridges at a price of 35.00 each. This is a 3-4 month cartridge. I would like to find a more economical alternative. I would like to be able to purchase the minerals in bulk (2-4 liters) and refill the cartridge as needed every 3-4 months. Is anyone aware of a vendor who sells Nature 2 in bulk? FYI, the dealer in my town, like many dealers, had no idea how to use N2 correctly. I was told to use chlorine shock rather than non-chlorine shock (MPS). That was exactly wrong. Here is what I believe to be the correct use of this product in my 7 person spa with ozonator: - 1 N2 cartridge every 3-4 months (close to 4) with change of water. - Maintain water temp > 100F (usually 103) - MPS non-chlorine shock @ 3 tablespoons once/week (MPS reacts with the minerals to form an effective oxidizer) - 1/4 teaspoon granulated chlorine 2-5 minutes before each use of the tub. When I fill my spa with fresh water I wait until it is up to temperature (> 100F). I usually give it another day then I adjust to the correct alkalinity using sodium bicarbonate (alk-up) purchased in bulk. In my area that takes approx 1 cup. Once the temp and alkalinity are correct, I place the N2 cartridge in the spa (there is a compartment that is made for it in the Sundance spa). After that I shock (MPS) once per week and adjust alkalinity as needed. I usually only need to adjust alkalinity one more time in a 4 month cycle. This is a very low maintenance system. The water is clean, clear, and free of bubbles for the entire 4 month period. AND, I no longer get itchy from the bromine I used to use. By the way, I believe the reason I never get bubbles in my spa is that I rarely let anyone in wearing a bathing suite. The residual soap from the laundry that is left on suits is the biggest source of contamination and bubbles. Not to mention that is just feels better in the nude. Cheers