Calcium hardness of zero ok?

[txborn]

I just got a new Hot Spring Spa and I used Hot Spring Vanishing ACT which you put in for 24 hours to absorb the calcium in the water. Calcium hardness after fill was 370. Calcium hardness after using the Hot Spring Vanishing ACT was zero.

Is it ok to have zero calcium hardness?

Thanks

 

[Guest]

Where did it go?

 

[chem geek]

I don't see Hot Spring Vanishing ACT on the Hot Spring website. Does it have a list of ingredients? I suspect that it might be a phosphate buffer since that will precipitate out most of the calcium as calcium phosphate. Did the water get cloudy or have sediment at the bottom and did you have to clean the filter?

So long as you don't have any plaster-like materials exposed to the water, then you don't need calcium in the water, but using a phosphate buffer isn't what we normally recommend and without the calcium you may find that your water has more foaming.

 

[txborn]

Water never got cloudy and no foam present. box says "Calcium remover for stert up and refill". You can google Watkins Vanishing ACT (Watkins manufacturers Hot Spriing) but not a lot there. It is a fabric sock weighing about 4 pounds filled with some sort of powder.

Also, this spa is now in Mexico where the pH was off the charts deep deep purple and TA of 340. Took almost 16 ounces of dry acid added slowly and about 2 hours of jet aeration to get it down to a pH of 7.5 and a TA of 70! All seems atable now but the pH does rise a bit after the jets run.

 

[chem geek]

OK, this doesn't look like a phosphate buffer, but something else that captures calcium in the powdered material in the sock (maybe some sort of ion exchange resin?). At any rate, you should find that your pH becomes more stable if the TA is lowered. If you are using the Dichlor-then-bleach method, then the TA should be quite a bit lower -- below 80 ppm and as low as 50 ppm if necessary, though you may not be able to find Borates (20 Mule Team Borax or Proteam Gentle Spa or boric acid) in Mexico (what is the spa doing in Mexico when it says you are in Texas? Did you move?).

 

[txborn]

LOL, it is at our condo on Isla Mujeres, a small island off the coast of Cancun. I bring down 20 Mule Team but can't check bags with dichlor. There is only trichlor here and the place in FL where I got the spa said not to use it so I am stuck with bleach only and a corona discharge ozonator as well as a silver ion cartridge in the circulation filter and use non-chlorine shock (Freshwater MPS chlorine free oxidizer from Hot Spring).

 

[chem geek]

If you are allowed to bring some CYA (aka stabilizer or conditioner) with you, then that would be good -- you only need a small amount to get up to 30 ppm and then enough to add around 5 ppm per month until the next water change. Using only bleach without any CYA in the water will be harsh on your spa, especially on your spa cover. It will also tend to outgas faster so the chlorine demand will be higher.

Alternatively, you can use your silver ion cartridge with the non-chlorine shock (MPS) for primary sanitation and then shock with bleach if needed (if the water looks dull).

 

[txborn]

Thanks for the info chem geek. There is no way to measure for MPS levels so I am not sure how much to put in and frequency. I will see if there is CYA available here today.

 

[chem geek]

There are MPS test strips (and the Taylor K-2042 MPS interference remover which can also be used to measure MPS itself) that you could take with you. Amounts needed are in the Nature 2 Owner's Manual. Obviously, using CYA and bleach would be less expensive, but at least you have alternatives.