Nature 2, Mps And Infrequent Use

[Rbrb]

We have a 500 gallon Hot Spring spa. I've switched over from using an ACE saltwater system to the Nature 2 cartridge. We use the hot tub infrequently -- maybe only 1x every 3 weeks or so. The Nature 2 guide says only to add MPS at use (right before and right after). If I am using so infrequently is that still ok, or should I add maybe once a week? I initially shocked the water with dichlor so currently there is residual chlorine. I want to try not shocking once a week with chlorine as we have an ozonator. Thoughts?

[chem geek]

You may need to add it once a week or so. Check the MPS level just to make sure it's not getting to zero as that's the way to know for sure. MPS will last longer than chlorine, especially with an ozonator that would otherwise deplete the chlorine quickly. There are MPS test strips you can use and for this purpose they are OK.

[Rbrb]

ok, thanks so much.

[Vista_Life]

I do about the same thing. We use ours a couple times a week but same treatment method. If it ever gets to be too long between soaks, I'll put MPS in it just to be sure there is some residual. The silver ions should keep some level of sanitation, as I understand it, but I consider that back up. I still do once a week dichlor (1 TBL)