Uncontrollable high pH with @ease SmartChlor

[htnj]

Before I delve too far into it here, I know the general feelings about the inline @ease bromine systems.

We just installed a brand new 2016 Artesian Pelican Bay spa with Crystal AOP system (Artesian Spas - DirectFlow Platinum Luxury Hydrotherapy Hot Tub), that includes an inline @ease. However, this is not the bromine version, it's a brand new 'SmartChlor' system, which, from what I'm told, is a new type of chlorine to the industry.

The problem I'm having is the pH rocketing up off the chart after any use of the tub, and by use, just running the jets alone for 15-30 minutes without people being in it. Let me also say I'm having an incredibly difficult time finding any information about this 'new' chlorine. This is about the only info I've gotten regarding this type of chlorine:

Di or Tri chlors have 2 atoms that split and immediately become free chlorine. This "smartchlor" allows for one atom to become free chlorine and the other stays in reserve. Thus, you tend to have a resting free chlorine reading of .5-1.0 (approx. the same as your tap water) but a reserve to total chlorine of 10-15ppm.

Where this becomes a benefit is that when you use the tub, the chlorine levels do not fall off a cliff. Rather it pulls from the free chlorine to keep a consistent level of approx. .5-1.0ppm. It handles heavy bather loads as well, since the free chlor can keep up with the burn up of the active sanitizer.

This allows for you to only have to shock with potassium peroxymonopersulfate (MPS) once a month. That is a nice benefit. However, it is also very much reflective of your pH level. While pH is always important to your sanitzier, as it is the the basis of how effective your sanitizer is is, its even more-so with @ease.

The tub has been filled about 2 weeks, and we've used it (up to 4 people at a time) maybe half dozen times for an hour or two each time.
The water has remained crystal clear this entire time, so I guess something is working.

However, as mentioned, the pH seems to be completely uncontrollable at the levels they recommend.
Per @ease SmartChlor, I see this:
pH 7.2 – 7.8
Total Alkalinity: 80 – 120 ppm
Calcium Hardness: 150 – 250
Total Dissolved Solids: <1500
*Free Chlorine: 0.5 – 1.0 ppm


I filled my spa initially with a PreFresh filter (city water) and initial testing had CH: 90, TA: 90, pH: 7.2. I added enough calcium to bring it up to the 150ppm mark, and TA increase to get 110ppm. AT this point I added to Frog jump start shock and let it get up to temp.
After it was up to temp, I added the mineral & chlor cartridges and tested everything the next day. It all seemed OK, so we started using.
I checked the next morning, CH, TA were consistent, but pH was so dark it looked almost purple. I did the acid demand test, determined enough to bring it down, added it, and all was well again.

But this keeps going on...use the spa, add acid, use spa, add acid, TA dropped too low, add baking soda, use spa, add acid...etc. (using dry acid)

Now I read the 'using chlorine in your spa' thread which states to do ~50ppm TA, but manufacturer of the chlorine states 80-120ppm. ANd I also read that too high TA is trademark bouncing pH symptom.

So does anyone have any ideas? Can I run with low TA so long as I'm balanced on the SI scale? I had my water tested by a local pool store, and no metals or phosphates or anything that shouldn't be there was found.
The other TA\PH\CH numbers all matched what I was getting. They also measured FC at 0.6 and CC close to 9; so it seems that's working as expected too.

Sorry for the long post, thanks for the help in advance!

 

[pooldv]

Yes, you should follow the instructions in the How do I use Chlorine in my Spa (or pool)? I've been maintaining my tub this way for a few years and it is great.

The idea is, after you fill lower your TA to 50, Pool School - Lower Total Alkalinity. This will help reduce PH rise. Then add 50 ppm borates which will further help to control PH rise. Don't skip the CYA, it helps.

 

[ant 83]

Well, this advertisement claims that there is three times the profit involved with this product over dichlor.

FROG SmartChlor - YouTube

Sounds like a scam to me.

As for PH being too high, my understanding comes from maintaining salt water fish tanks. I don't know if fresh water is different, but in salt, the higher the alk, the higher the PH. They are directly correlated, with the PH being higher or lower depending on how much carbon dioxide in dissolved in the water. Co2 levels come to an equilibrium with the atmosphere, which is accelerated from aeration.

There are charts that show this on this page: Low pH: Causes and Cures by Randy Holmes-Farley - Reefkeeping.com

Lower your alkalinity, and your PH will be lower.

I will also note, that if I was in the business of selling fancy labeled baking soda/dry acid, that telling people to maintain high alkalinity, will increase volume sold of both products.

 

[htnj]

Yeah, I get what you're saying. The monthly cartridge runs like $13, but my dealer gave me a year of them.
It does "seem" to be working as advertised for the most part. My water has remained clear with moderate use (~4 times a week about an hour each time.)

Sometimes its just 2 of us, other times has been 4. The FC does seem to be maintaining anywhere from 0.4-0.6 ppm testing with DPD test.

I'm going to try some boric acid, and get my TA down to the 50ppm mark or where it wants to be. I just wish there were some other 'real world' accounts of this system, other than the dealers word.

 

[tim5055]

Well, looking at the MSDS of the product it appears to be a version of Dichlor

Show Active Ingredients

I'll leave the deciphering of the exact contents to one of our "science" guys.

 

[ant 83]

It does "seem" to be working as advertised for the most part.

Even so, I am still skeptical. They don't say how this works, just a bunch of gibberish about not having to test for chlorine, and "self regulating".

Come on.

The stuff is probably just dichlor mixed inside a block of salt that dissolves when the water jets are on.

A salt water generator would work like how they claim I think, if used with a timer, that matched up with bather load. CYA at an appropriate level would add a buffer zone to the chlorine levels, and make it possible to double check with a test kit.

This frog stuff is not worth the bother from my perspective. I'm not going to take any chances with my health, with their misleading advertising mumbo-jumbo.

 

[JoyfulNoise]

The main ingredient is dichlorodimethylhydantoin. This is a spa chlorinating product (68% available chlorine) typically used in bromine spas to act as a chlorine source for reactivating bromine (oxidizing bromide back into bromine). It is acidic in water and will form solutions with a pH of around 4.4. DMH (dimethylhydantoin) does not "stabilize" chlorine with respect to UV light nor does it act as buffer for chlorine like CYA does, so, while this compound will add chlorine to your spa water it will also add DMH (dimethylhydantoin) which serves no purpose.

Typically speaking, the "Dichlor-then-bleach" Method we advocate here is cheaper but, if you already have these cartridges, then I see no issue with using them other than you will need to carefully monitor your pH and TA to ensure that your TA does not crash from the acidity of these cartridges.

 

[jblizzle]

I just want to point out that clear water does not does not necessarily mean the water is sanitized and safe. It just means you don't have algae.

 

[htnj]

I just want to point out that clear water does not does not necessarily mean the water is sanitized and safe. It just means you don't have algae.

Oh, I'm aware of that, but I have had my local pool store test & confirm my readings. Twice now.
I'm not sure what software they're using, but the printout I get is all BioGuard, and all the recommended adjustments for now and maintenance all reference BioGuard products.

So I guess it's their software the pool store is using.

Thanks JoyfulNoise, I do monitor and will continue to do so. Do you see any possible interactions between it and adding boric acid to help stabilize pH or do you see no appreciable effect?

 

[JoyfulNoise]

Dimethylhydantoin (DMH) has a fairly high pKa (~9.0). Therefore it will act a lot like boric acid/borates in that it will buffer the water against rising pH. However, it has limited buffering capacity for falling pH so if you add any acidic sources of chlorine, you'll still need to keep a careful watch of pH and TA. There is no significant interaction between DMH and the borate anion and so they can effectively be treated as separate species. There are no test methods I'm aware of for testing DMH levels so, you'll have periodically dump your spa water to keep that in check.

 

[htnj]

Dimethylhydantoin (DMH) has a fairly high pKa (~9.0). Therefore it will act a lot like boric acid/borates in that it will buffer the water against rising pH. However, it has limited buffering capacity for falling pH so if you add any acidic sources of chlorine, you'll still need to keep a careful watch of pH and TA. There is no significant interaction between DMH and the borate anion and so they can effectively be treated as separate species. There are no test methods I'm aware of for testing DMH levels so, you'll have periodically dump your spa water to keep that in check.

When the water was analyzed, it showed 10ppm borates, but I have not added any to date. I wonder if that is the DMH showing up or is there some naturally occurring sources in my water supply...guess I'd have to test that too.
I do plan on 3-4 month water changes as standard procedure.

 

[JoyfulNoise]

No, DMH would not show up in a borate test. I think what you're seeing is either simply pool store testing error (they are not very good at any test other than pH as far as I can tell) OR you actually do have 10ppm borates in the water. Many package spa chemicals are often mixtures of some primary disinfecting ingredient (like the DCDMH) and other pH balancing chemicals like sodium carbonate, bicarbonate or borates. There are quite a few chemicals for spas and hot tubs that have borates in them and, under some circumstances, can be labeled as a "trade secret" and so you wouldn't know what they are necessarily.