non-toxic hot tub chemicals

[jimbusch]

i am new to these forums but wondered if anyone has experience with using non toxic chemicals in their hot tub? i google searched the topic and came up with ahhnatural.com. has anyone used their system? does it work? is it cost effective?
if anyone has other non-toxic chemical options i would love to know your thoughts and experience.
thanks, jim

[chem geek]

Do you mean non-toxic to bacteria, viruses and other pathogens?

ahhNatural uses "natural minerals including the antioxidant vitamin C and ancient sea salts".  You also need to add an oxidizer weekly and they recommend hydrogen peroxide (an oxidizer will effectively get rid of the vitamin C which is a reducing agent so you need to add more of that during the week).  They claim there is a mineral in the pad that absorbs ammonia.  This page makes a claim that "The ahhNatural system is designed to kill unwanted organisms without the exposure to chemical additives."  Their product is not registered with the EPA let alone passing DIS/TSS-12 as required for any product to make disinfection claims.  I've reported this to the EPA compliance organization.

If you truly want a system that minimizes chlorine use, yet is EPA-approved as a disinfectant to quickly kill bacteria, then use Nature2 with non-chlorine shock (MPS) as directed.  You only need to use chlorine infrequently, perhaps once a week or so, to oxidize any excess bather waste or other byproducts not handled by the non-chlorine shock.  If you keep yourself clean and don't enter the spa with lotions, then the non-chlorine shock should handle things better and you won't need chlorine as often.  There are only four EPA-approved disinfectants for spas: chlorine, bromine, Baquacil/biguanide/PHMB, and Nature2 with MPS.  It is the silver ions in Nature2 combined with MPS at hot spa temperatures that provide the fast enough kill rates to gain EPA approval.

The only reason companies like ahhNatural can exist is that there are no regulations regarding what you do with your residential spa (or pool).  You can soak in raw sewage as far as the government is concerned.  The only regulations are FIFRA rules in product labeling (and associated literature, including websites) that prevent any claims of disinfection/sanitation ("killing bacteria", etc.) without EPA approval (registration of the product as a pesticide such as listed in the PAN Pesticide Database where the EPA registration number can be used to look up the Pesticide Product Label) and in particular for pools and spas that means passing EPA DIS/TSS-12.  There are some products, mostly those using copper ions, that have EPA registration numbers, but they cannot make disinfection/sanitation claims and generally say things like "controls bacteria" or "kills algae" instead as the EPA registration numbers are for use of such products as algicides.

Richard

[jimbusch]

thanks richard. i have looked at the nature 2 product as well as eco one. any preference? there was another thread talking about eco one that i read yesterday.
thanks again,
jim

[chem geek]

On this ecoone® webpage they say the following:

effective:  Simple and safe are easy enough to accomplish when dealing with water chemistry. To get around the problems of algae, bacteria and water clarity, simply drain and refill your pool or spa every time you use it just like your bathtub. But try to imagine what the water would be like if you only drained your bathtub every three months? Well, that's basically what you're asking of your spa. Our ecoone systems, through advanced chemistry manage to combine the best of nature and science to create what we believe is the most effective system available on the market today. ecoone: Putting the 'sanity' back in water sanitation.

You will note that they make no claims of killing bacteria or even controlling them other than by complete water replacement.  On this web page they say the following:

While ecoone® eases the oxidation demand on your sanitizer it is not a registered sanitizer. Maintain the minimum recommended amount of sanitizer in your spa.  This may range between .05 ppm and 3 ppm depending on your local regulatory agency guidelines.

That is, this system is not chlorine-free (or bromine-free) and is not EPA-approved for use in spas by itself.  They are basically enzymes to help with oxidation, though ozone helps with oxidation as well.  With the Nature2 with MPS system, it is the MPS that does the oxidation (unless you have an ozonator that also helps with oxidation) and it is the combination of silver ions from the Nature2 cartridge with MPS at hot spa temperatures that disinfects the spa water.

While there isn't as much written on forums on EcoOne, there is a lot on a metal ion system that uses copper called EcoSmarte (similar to the "minerals" that ahhNaturaly uses).  EcoSmarte uses only copper ions and does not use silver ions at controlled concentrations in conjunction with non-chlorine shock (MPS).  It is not an EPA-approved disinfectant/sanitizer for pools or spas.  There are MANY threads written up on multiple forums about EcoSmarte, though most are about pools.  I list many of them below if you are really interested.

PoolSpaForum.com
Ecosmarte Oxidizer
Ecosmarte Systems?
Ecosmarte System Pros and Cons
Ecosmarte
Ecosmarte System
Hot Tub Maintenance With Ecosmarte System Questions

The PoolForum
Ecosmarte?
Ecosmarte or Salt system?

Swimming Pool Help Forums
Ecosmarte
Can't seem to stop algae in Ecosmarte pool
ECOsmarte water purification systems feedback

Trouble Free Pool
converting my ecosmarte system to chlorine
I've had it with Ecosmarte!!!
Ecosmarte in Spain
A New Pool Owner with Ecosmarte--it does work.
We got a sales pitch for converting to Ecosmarte
Ecosmarte
Copper and silver based ioniser system (Ecosmarte and such)
Intellitouch Ecosmarte UV-C Amalgam

Regarding the Nature2 system, you can look at their Owner's Manual to read how you initially shock the cartridge with chlorine to activate it, then subsequently use non-chlorine shock (MPS) at maintained levels for sanitation (in conjunction with the silver ions from the Nature2 cartrdige).

Richard

[chem geek]

With the exception of silver ion with MPS at hot spa temperatures, metal ions do not kill pathogens quickly enough and are are not used (by themselves) in commercial/public pools since they may not be able to prevent person-to-person transmission of disease.  When the FC is around 10% of the CYA level, most common heterotrophic bacteria are killed by chlorine in under one minute (for a 99% kill).  At concentrations in pools/spas, it takes silver ion around 10-20 minutes and copper ion around 40 minutes for an equivalent kill rate.  Also, metal ions are not effective (at normal pool/spa concentrations) at inactivating viruses.  For example, this paper shows that copper ions do a 90% inactivation of Herpes Simplex Virus in 30 minutes at 100-200 ppm, but that is far, far higher in concentration than found in pools (copper is usually < 0.3 ppm in pools).  This paper shows that silver ions have virtually no effect on vacciniavirus, adenovirus, VSV, poliovirus, HVJ, but that with herpes simplex virus there is a 5-log kill in 60 minutes (roughly a 90% kill in about 5 minutes), but at over 3200 ppb compared to the usual limit of 20 ppb to prevent silver staining.

You can read more about copper/silver ion systems and why they are not used in public/commercial pools/spas on their own on the Australian APVMA website and on the Health Canada website.  There are no standalone copper or silver ion systems for pools that pass the U.S. EPA DIS/TSS-12 due to their slow kill times (Nature2 with MPS for spas being the ONLY exception for spas only) and all copper/ion systems certified by NSF Standard 50 require a minimum of 0.4 ppm chlorine or 0.8 ppm bromine.

Realistically, it's a spectrum of risk and you are much better off using a metal ion system than using nothing at all, but the risk is much higher than using one of the only three disinfectants registered by the EPA for use in pools: chlorine, bromine or Baquacil/biguanide/PHMB or the one additional one approved for spas: Nature2 with MPS.

Richard

[Spatech_tuo]

thanks richard. i have looked at the nature 2 product as well as eco one. any preference? there was another thread talking about eco one that i read yesterday.
thanks again,
jim

There are a few products out there designed to take advantage of the unwarranted fears people have about spa water treatment. Chlorine does a great job on the water that comes out of your faucet and the water in your spa and using it in conjntn with ozonators and Nature 2 makes life even easier. Used properly you won't use much and when I go in my spa there's about as much chlorine in the water as I'd get if testing the water flowing into my kitchen sink.

[Shaamus]

chem geek,

What are your thoughts on the MPS/dichlor mix products like Leisure Time Replenish and Spa Guard Enhanced Shock?  Straight MPS with Nature2 has a tendency to eventually offer up a musty smell, but cutting with a little dichlor seems to help.  These mix products obviously already have a little dichlor mixed in.  The Nature2 directions recommend shocking occasionally with dichlor while dosing with the MPS.  In your opinion, what is "science" behind having both already mixed together?

[chem geek]

If you are using Dichlor mixed with MPS then you are really using chlorine for the sanitation and the MPS is there to supplement with oxidation.  That is fine so long as there is a residual of Free Chlorine (FC) measured between soaks, but if you are only measuring an MPS residual, then this isn't as good unless you've got silver ions in the water (such as from N2).  Basically, think of the combination of silver ion with MPS as being as potent as chlorine.  MPS alone is NOT as potent as chlorine.

Yes, some people note that N2+MPS doesn't keep the water quite as fresh as chlorine which is why chlorine is added periodically, but it's really the only "very sanitary" approach that doesn't use chlorine most of the time.  For people that really want to avoid chlorine, it's an alternative that is still sanitary.

Now in practice, one can achieve much of the same effect using chlorine but having the Free Chlorine (FC) level drop to around 1-2 ppm before one soaks -- one does this by adding only enough chlorine after a soak such that the level is 1-2 ppm before the next soak (you don't want it any lower than 1 ppm before the soak, however).  That way, it isn't high enough to be objectionable to most people and so long as you add chlorine right after the soak you don't give enough time for any pathogens to reproduce to any significant numbers -- note that you aren't preventing person-to-person transmission during the latter part of the soak with this approach.  However, if one uses Dichlor-only, then the buildup of Cyanuric Acid (CYA) in the water will make the chlorine less effective over time.  That's why the Dichlor-then-bleach method works well to have the water remain fresh for at least twice as long as Dichlor-only and it's more sanitary as well since the active chlorine level remains fairly constant after the first week of Dichlor-only that builds up the CYA level.