Eco- And Human- Friendly Spa Treatment?

[samuelclemens]

Hi there. Allow me to begin by saying that I am a hot-tub newbie and a chemical dunce, so please, please go easy on my silly questions and respond in plain English if you are able...

I moved into a co-op where the previous owners left an older Infinity Spa (can't find the model number) with, I think, no Ozonator (it looks like there are both electrical and pipe hook-ups for an ozonator, though).

We are going to start using it again, but we try to minimize the damage we do to our environment and our bodies through the use of toxic and especially carcinogenic chemicals and chemical by-products (I know, I know, just by running an old hot tub we are gulping up water and power, but sometimes you try to be hypocritically responsible, or responsibly hypocritical, or something). Also, one of my roommates has severe sensitivities to chlorine. I'm not sure if she was just overreacting to a single bad experience in the past, like poor ventilation or something (she is also a tiny person), but I don't know if anything will persuade her to give chlorine a try.

So, with all that out there, what is the most eco-friendly and non-toxic way of treating a tub, preferably without chlorine? Remember that I am completely clueless here, so step-by-step instructions in plain English with recommended dosages and schedules would be very much appreciated. I am at your mercy...

[waterbear]

There are only 3 EPA approved sanitizers--chlorine, bromine and biguanide.

Bormine is a known senstizer (most likely to cause a true allergic reaction) but is a good choice for indoor tubs and ones that are not subject to full sunlight.

Chlorine has less of an odor than bromine and is my first choice for outdoor tubs. IF ventialtion is poor indoors the air quaitly can degrade with chlorine. It is simpler to use than bromine but does require daily water checks to make sure the chlorine levels are maintained.

Biguanide is an antimicrobial that is used with a hydrogen peroxide oxidizer. It is more expensive than either chlorine or bromine, will require much more frequent filter cleaning and replacement, and has a tendency to develop white water mold and pink slime since bacteria deveop an immunity to it after continued use.

ALL other systems are NOT primary sanitizers metals (or 'minerals' as the marketing hype likes to call them. "Minerals" sound very spa like and healthy but the truth is they put metals into the water for sanitation. Metal ions have very slow kill times and need to be used with a residual santizer like chlorine. If you want to soak in copper sulfate and silver nitrate be my guest! These are the actual ingredients on the box of a Nature2 cartridge, a popular 'mineral' sanitizer!), ozone, UV light are all secondary sanitizers that need to be used in conjucntion with a primary sanitizer, usually chlorine or bromine. Be aware that not all secondary santizers are compatible with bromine or biguanide.

Chlorine is, IMH0, the safest sanitizer to use with bromine running second both in terms of chemical exposure and water sanitation when used properly. Biguanide works but I feel there are just too many problems associated with its use so unless you have a TRUE chemical sensitivity to both chlorine and bromine I would avoid it.

Much of the bad press that chlorine has recieved concerning disinfection byproducts such as chloroform and other TMHs are more of a concern in drinking water treatment and, to some extent, indoor pool where they can concentrate in the air than in outdoor pool or spa use. Also, Ozone can create bromates and chlorates in the wate r which are other non desirable disinfection byproducts, once again more of a concern in drinking water.

[samuelclemens]

Thanks, Waterbear. I will pitch this to the housemates and see what comes out of it.

Also, Ozone can create bromates and chlorates in the water which are other non desirable disinfection byproducts, once again more of a concern in drinking water.

Does this suggest that an ozonator would be a bad idea? Or, with my priorities, is an ozonator something we should look into?

[waterbear]

Ozine is NOT a stand along sanitizer since there is no reisudal. Also realize that ozone ia a toxic gas. Ozone works differently with chlorine and bromine. In a chlorine system ozone can reduce sanitizer demand because it does kill some pathogens but it also destroys chlorine so chlorine usage might be higher to maintain the same residual sanitizer level.

In a bromine system ozone will oxidize the "bromide reserve" that is put in the water on each fill (sodium bromide) into active bromine sanitizer, hypobromous acid. This can help maintain more constant bromine levels but it also causes the oxidation of hypobromous acid into bromates. Bromates are a suspected carcinogen in drinking water but you are not drinking the hot tub water. Keep that in mind.

Ozone is usually considered a worthwhile addition but it is by no means necessary.