Heads a spinning around MPS and Chlorine Chemistry

[SPA-NUT]

So I recently purchased a new 225g spa, it came with the Frog @Ease system. We didn't care for it / could never get dispensing to be consistent either poor water quality or harsh chemical effects. I purged the system after the freebie cartridge ran low and started anew. I've been doing my own regiment now for almost a month (9/28). After much reading I opted to go with trying the Nature2 mineral system and MPS as my oxidizer with this new fill. In the process mistakes where made... I misunderstood the relationship between the MPS and need of Chlorine. I had this understanding that you could substitute the Chlorine with a Non-Chlorine product. I quickly learned I need to activate the system with Dichlor, I was like ok that's just an activation... I then went on to use the spa with a weekly test practice and dumping my MPS as a form of shock the following week (😰). Needless to say the water quality went south quick and I knew something was off and began digging. Fast forward to now after shocking the system properly with DiChlor and getting parameters back in line I'm questioning the whole aspect of MPS vs going straight Chlorine given my false understanding. That said, In the interim I wouldn't mind giving it a fair go for a bit now that I have a better understanding (I hope :P) of things, not to mentioned already having purchased products. But what brings me to this post is my FC value, I tested it a few times today with mid day being at 12.2 and this evening being at 10.0. I was thinking that was way high given the ideal value of 2-4ppm (from Taylor K2006) but then I noticed in nitro's post HERE stating to use Dichlor to continually raise FC til 34 then swapping to Bleach, this is obviously much higher than 4ppm. My test kit's limit for FAS-DPD testing is limited in range from 0-20ppm for FC, so now I'm totally confused. I could really use some help as I feel like I'm hitting information overload and not knowing which way is up anymore. 

I do have the Taylor Deox Reagent for MPS testing, while it involves a good deal more drops I would like to continue to use that system a bit longer to see how it goes, maybe 4 weeks putting me at least to the 2month mark on this fill. Then or thereabouts I'd like to swap over to the Dichlor/Bleach method but I'm not sure If I would need to do a system flush early at that point to see how things are absent of MPS all together, especially on the testing side. I'm still somewhat dumbfounded by the MPS needing Chlorine and trying to wrap my head around what's the point then of it...

 

Here are my latest test results 10/13:

Temp 99d

TA 90ppm

Ph 7.6

FC 10.0

CC 0.4 (waiting to see if this falls further after early day shock)

MC 3.0

CYA 30ppm (as of 9/28 - not retested today )

CH 140ppm (as of 9/28 - not retested today)

[waterbear]

4 hours ago, SPA-NUT said:

I noticed in nitro's post HERE stating to use Dichlor to continually raise FC til 34 then swapping to Bleach,

 

use dichlor until the CYA level is 20-30 ppm then switch to bleach for your chlorine source since it will not further raise CYA. Nitro was merely stating that once you have added a TOTAL of about 34 ppm FC OVER TIME, not all at once, you will have achieved your desired CYA level and it's time to switch over to bleach. For every 10 ppm FC added by dichlor you are adding 9 ppm CYA. If you are maintaining a 4 ppm FC level daily and are losing 2 ppm daily and need to add 2 ppm back then you will add a total of 34 ppm FC in 17 days. If your daily chlorine demand is 1 ppm then it will take 34 days of dichlor. This assumes you are starting with a 0 ppm CYA level. Hope this clears it up for you.

Nature 2 allows you to run your FC at .5 ppm but, IMHO, there is not enough residual FC in the water at that level for fast disinfection  and quick kill times for some of the the enteric pathogens introduced into the water by fecal matter on bathers (no matter how clean they THINK they are) and the silver ions have a slow kill time and are not effective against viruses. The copper is basically algaestatic. Ditch the N2, use Nitro's dichlor/bleach method, and save a lot of money in the long run!

[SPA-NUT]

 

7 hours ago, waterbear said:

use dichlor until the CYA level is 20-30 ppm then switch to bleach for your chlorine source since it will not further raise CYA. Nitro was merely stating that once you have added a TOTAL of about 34 ppm FC OVER TIME, not all at once, you will have achieved your desired CYA level and it's time to switch over to bleach. For every 10 ppm FC added by dichlor you are adding 9 ppm CYA. If you are maintaining a 4 ppm FC level daily and are losing 2 ppm daily and need to add 2 ppm back then you will add a total of 34 ppm FC in 17 days. If your daily chlorine demand is 1 ppm then it will take 34 days of dichlor. This assumes you are starting with a 0 ppm CYA level. Hope this clears it up for you.

Nature 2 allows you to run your FC at .5 ppm but, IMHO, there is not enough residual FC in the water at that level for fast disinfection  and quick kill times for some of the the enteric pathogens introduced into the water by fecal matter on bathers (no matter how clean they THINK they are) and the silver ions have a slow kill time and are not effective against viruses. The copper is basically algaestatic. Ditch the N2, use Nitro's dichlor/bleach method, and save a lot of money in the long run!

 

 Thankyou Waterbear, I was obviously missing that key point of adding 34ppm in total over time as opposed to raising it to 34ppm as a delivery method to achieve the desired CYA levels. This makes a lot more sense now, guess I was on information overload yesterday and got sideways looking at everything. 😂

Sounds like my next step is to test my water parameters again and see if my FC and CC has fallen down in level. That and to see where my FC demand is at. What is maximum FC for entering water? I've read elsewhere 5 but then also info stating at 10 it fades swimsuits, seems like in Nitro's writeup he states "The rule of thumb is, assuming CYA is 20-30 ppm, FC should normally be between 3-6, with a min of 1 and shock to 12 once a week" but also states some examples of a party needing 7ppm and 20ppm per person per hour under differing conditions. So is there a dangerous level of FC to enter the water? I follow you in these examples we are building a high level up to act as a buffer for the high demands but the comment i read elsewhere of 10ppm fading swimsuit leads me to believe there is a problem with entering the water with to high of an FC. Could you or somebody please elaborate on FC values more.

Thank you all for this information on these forums

[waterbear]

10 ppm will fade swimsuits when CYA is 0 ppm

at 20 ppm CYA a FC level of 20 ppm might fade a swimsuit but should not hurt a swimmer

at 30-50 ppm a FC level of 30 ppm FC could be damaging to swimsuits and tinted hair but I would go in that water naked from the neck down. I would rinse off after.

As far as dangerous FC levels go look up bleach baths. They are a treatment for skin conditions such as chronic eczema, staph, and atopic dermatitis and are considered safe by such places as Mayo Clinic and the American Academy of Dermatology Association for both children and adults. the normal dose is 2 to 4 oz of 6% household bleach in 40 gal of water. This  would be 24-48 PPM FC with NO CYA! Soak time is usually 10-15 minutes from the neck down followed by a water rinse 2-3 tines a week.

[SPA-NUT]

OK one more question regarding the Nitro's Post perhaps you know the answer to. There's recommendation to add borates to a value of 50ppm to act as a buffer and make the water feel silker. This sounds appealing to me but how does one test for borates? Perhaps I missed it in the post somewhere... Borates don't seem to be a typical test parameter in kits.

[SPA-NUT]

On 10/14/2020 at 10:47 AM, waterbear said:

10 ppm will fade swimsuits when CYA is 0 ppm

at 20 ppm CYA a FC level of 20 ppm might fade a swimsuit but should not hurt a swimmer

at 30-50 ppm a FC level of 30 ppm FC could be damaging to swimsuits and tinted hair but I would go in that water naked from the neck down. I would rinse off after.

As far as dangerous FC levels go look up bleach baths. They are a treatment for skin conditions such as chronic eczema, staph, and atopic dermatitis and are considered safe by such places as Mayo Clinic and the American Academy of Dermatology Association for both children and adults. the normal dose is 2 to 4 oz of 6% household bleach in 40 gal of water. This  would be 24-48 PPM FC with NO CYA! Soak time is usually 10-15 minutes from the neck down followed by a water rinse 2-3 tines a week.

I see so its more of a relationship then just a singular value, interesting. Seems I'm learning all sorts of new chemistry aspects

[waterbear]

The chlorine/CYA relationship is exactly that. The higher the CYA the higher the FC needs to be run for the same net effect in the water. There actual tables that have been published illustrating this.  The original one was done by Ben Powell of The Pool Forum/PoolSolutions and refined by Chemgeek and published on TFP. Here is a link that shows both:

https://blog.intheswim.com/fresh-thoughts-on-cyanuric-acid/

Much of the original research to support this goes back to the 60s but was suppressed because it could cut into the profits of one of the largest manufacturers of stabilized chlorine products for swimming pools.

22 hours ago, SPA-NUT said:

OK one more question regarding the Nitro's Post perhaps you know the answer to. There's recommendation to add borates to a value of 50ppm to act as a buffer and make the water feel silker. This sounds appealing to me but how does one test for borates? Perhaps I missed it in the post somewhere... Borates don't seem to be a typical test parameter in kits.

LaMotte Borate test strips are the best ones out there. They have a color change from pink to tan vs. the Hach, Aquachek, and Taylor strips for borate which have a color change of very close shades of tan and are next to impossible to read. You will probably have to order them online. Running your TA around 50-70 ppm and borate 30-50 ppm AND keeping your pH NO LOWER than 7.6 and only lowering it down to 7.6 when it climbs ABOVE 7.8 will give the the best stability. The combination of low TA and borate will keep your pH around 7.7 for a longer time than without. pH rise is caused by outgassing of CO2. The higher the TA the higher the forced carbination of the water and the faster the outgassing of CO2. The lower the pH the higher the conversion of bicarbonate ions (TA) to carbonic acid (CO2 dissolved in the water) and the faster it will outgas. Aeration (bubblers, jets, air intectors) speed up the outgassing in much the same was that shaking a bottle of carbonated soda causes the dissolved CO2 to gas off.