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It can be done either way, I prefer using dichlor after each use, or better would be a floating system such as the @Ease SmartChlor/Mineral system. Shocking after each use can work but you always want to leave the cover off for 20-30 minutes after shocking, this may become a chore if you want to get out and close up the hot tub. You also want to leave the cover off for a little bit when adding dichlor, but not quite as important as when you shock it in my opinion. If you can use a floating system such as the @Ease it will make it so you won't have to sit around and wait t close the cover after adding chemicals.
The only thing I'd add to this is what is your goal? The main point of Nature 2 is to use a less-harsh chemical to sanitize. In my own words, N2 is a "passive" sanitizer, keeping the water clean when you are not in it. When you introduce the human element into it, the "active" sanitizer helps compensate.Dichlor is fine, but it will have more of a "chemical-y" smell vs, MPS which will also be softer on the skin.To me- That is the major factor in which way you go.Furthermore- If you go Dichlor, you really don't need the N2 cartridge. It doesn't hurt, but I just don't see the need for the extra expense.Just something to consider. Everyone here has given solid advice so you're in good hands. I hope this helps. Good luck moving forward.
Water Boy-dichlor is probably almost as bad on the cover, pillows, etc as shock, so I would recommend leaving the cover off after using it as well. Most customers I see are using bromine and if they ever complain about pillows going bad or decals on the control panel or other parts of the spa wearing, I always ask "do you leave the cover of when you shock?" and they always say "no one told us that". I'm convinced MPS shock is harmful if the cover is not left off for 20+ minutes. If you're shocking after each use you're probably only adding an ounce, so maybe it's not as bad as the 3-4 ounce weekly shock that we would recommend when using bromine.
I've been switching All my customers that use spa frog to @ease. Been working great with minimal shocking. I even started using it in my own spa. Having much better results then with the bromine frog system