Cleaning The Pool: Newsletter Challenge (02/05/08)

This is not a challenge. There are many schools of thought on the subject and each has their plusses and minuses.

The most popular choice is salt (salt chlorine generator). This provides chlorine from the salt at a low level that is less irritating to the skin and eyes (your body's fluids are saline anyway). The following link gives some of the features of the system and how it works.

Salt Pools

There are other systems, including one that uses copper. Some uses ionizers, oxidizers, and UV has been a method used in the past, too.

All of those systems work, but struggle to do the job as well as chlorine. I looked into the copper systems by Ecosmart, but found many owners had issues, particularly in warmer climates.

So far the salt systems have the majority of sales in Florida and it is something I am considering as a cost saving measure. Using chlorine is tricky because the concentration levels tend to bounce around due to usage, rain, and sun. For my pool the conversion is about $1,000 to $1,500, so it will take 3 or 4 years to pay itself back, but less work to maintain.

One that you missed, and I don't know if it would be applicable here: Sodium sulfite added to the pool water will generate sulfur dioxide that will kill alga, bacteria, etc. Then run the pool filter overnight and let the SO2 escape from the water, and the pool should be fine. One would likely have to adjust the pH after decontamination also.

WHat about stabilized Bromine, as a preventive measure by starting with a clean pool, a very low concentration will prevent biofilm to get a grip.

I would doze it with ozone and hope Juanita's skin can handle it.

Same problem with my ex wife who now has custody of the hot tub.

She couldnt handle the chems.

The spa store suggested the ozonator, a box with a germicidal UV tube

through which air / generated ozone passed on its way to the water

by way of a venturi. Never used chemz from that day on.

I Highly recommend it!

There are many Germicidal UV systems out there that would work in this application.

The byproduct ozone that may be generated by the high intensity UV is readily removed.

This process is often used to provide ultrapure water for phamaceutical companies and laboratories.

Tony L

"This process is often used to provide ultrapure water for pharmaceutical companies and laboratories."

UV does not purify significantly - and if the water was truly pure it would be irrelevant.

What it does do is ensure that reasonably pure water is ultra-sterile.

So far as pools are concerned, it sterilises the water leaving the purification plant, but has little impact on bugs that live on the pool liner (or in the grouting). Most pools also require a "wandering" mechanical scrubber to keep the levels on the walls under some sort of control. Maybe the scrubber could be combined with a UV source?

Putting a mobile device into the pool that is powered by electricity is a little scary.

You would have to use intrinsically safe techniques - isolation, LV plus??

I agree. However, how do you make it idiot-proof so that you can't accidentally have UV exposure? I am thinking that our eyes are vulnerable to any UV leakage.

Difficult one that.

I can't think of a method other than disabling it when the pool cover is not fully across.

Perhaps someone can build on combining a pressure sensor with an acoustic system that checks both the presence of water and of a hard solid at the correct distance?

Um in Australia we have had scubbers like this for past 30 odd years, creepy crawly, barracuda are a few name brands...

Curious. Nearly everywhere else the pump is stationary and the scrubber itself is water-driven.

Commercial water treatment systems are starting to use ultraviolet light to kill all the organizisms in water. Get a 500 watt UV purifier and put into the flow stream of the filter. The UV unit is basically a light in a tube. The pump may need to be upped in capacity, but the UV light can also ack as a heater too.

This would certainly leave the water a bit better tasting than salt, for those times you forget to close you mouth.

You only need 2500 - 3000 parts per million salt concentration so you can barely taste that at all. It is nothing like the ocean.

UV gets expensive with electricity and the lamps loose efficiency. Additionally, you still need to add something to sanitize the pool because only a portion of the total water is actually sanitized. It takes a long time to circulate the whole pool's water. Finally, UV will not stop the algae from growing on the pool walls. So, you are resigned to add chlorine or some other algaecide to keep that in check.

The above problems are also the problems with the EcoSmart system.

Even standard chlorine is not that bad if, and that is a big if, you keep your eyes on the chlorine and pH levels like a hawk. You don't need excessive levels to keep your pool sanitized and crystal clear, but the problem is keeping the levels constant in a dynamically shifting environment. So we tend to overdose it, then the levels drop, overdose it again, and it is a vicious cycle.

The other half of the pool equation is pH levels. EcoSmart is really fussy about pH. Salt systems are more resilient to pH fluctuations. I don' know about UV, but we already know that you still need to add chlorine or bromine/copper to keep the algae in check, so what does that give you as an advantage when you develop rashes to bromine and chlorine? Copper also stains the pool if you add too much.

Can algae etc. can be kept down with periodic overnight Cl2 dosing + neutralisation cycles to leave a minimum safe level of salts during the day, or is this a ridiculously expensive solution?

My understanding is that salt water pools require virtually no additional algae control.

My neighbor has the salt system and claims very little maintenance, or at least lower maintenance compared to standard chlorine treatments.

My family and I really don't have reactions to chlorine, but I want lower maintenance costs and effort to keep it clean. If I lower my chlorine level too (i.e., salt, etc.), then that is a bonus.

Wouldn't that depend on the local climate? In damp subtropical regions I understand that pure-NaCl would either require higher levels of salt than most people like, or some type of supplement.

Yes that is true with UV but also with salt systems, the salt does not kill all algae and definitely does nothing to control bacterias. The chlorine can do both but the salts will have to supplemented with other methods to get rid of the bacteria or you can get very sick from your pool.

So salt is definitely not the panacea that is first proposed.

Are you sure? My understanding is the salt is used as the chlorine generator. Water (with a very mild concentration of salt) is passed over a set of specially coated plates, which generates an electric current that breaks down the salt and water into their basic elements to form hypochlorous acid, which is the active sanitizer in all forms of chlorine.

So the pool does have chlorine, but it is derived by the salt. The big advantage is that the level of chlorine is very low, but the concentration levels are very steady and more resilient to pH shifts in the pool.

The concentration of salt used is very, very low. You can barely taste it.

Like I said, this is not the only way to treat your pool without adding traditional chlorine, but it is one of the more common ways to do it and supposedly at a lower maintenance cost.

Agree. This system was used extensively in the magnificent climate of Zimbabwe and worked well (actually nothing works there anymore), but has found little favour in the more tropical like climates of the East Coast of South Africa.

This tends to negative the original reason for the blog. The child is sensitive to trace amounts of chlorine, which is what the chlorine additives do. It is chlorine in an ionic state which the additives generate chemically that the salt will generate electronically. So for the sake of this blog, you can use the salt, but you can not ionize the chlorine out of it as suggested.

If the child is that sensitive to chlorine that she can not swim in a pool, the child would also have problems with normal tap water, as it is treated with chlorine. They would have to neutralize or filter the chlorine out of the drinking water to keep the child safe.

Reread the challenge puzzle. It stated that "She was unaffected by very low levels of the chemicals".

So, salt ionization seems to fit the requirement (as do a few other systems).

I agree. UV is the safest non allergenic method for purifying large quantities of water. These systems are widely used used in bottling plants where the flow rates are in thousands of gallons per hour.

Well, you still need to add an algaecide because UV will not stop algae from growing on the pool walls.

The pool walls do not pass through the UV chamber, so they are never sanitized.

This is the same problem with EcoSmart, ozone, and other systems that rely on passing pool water through any chamber for sterilization.

Very true, however the question was about reducing or eliminating the lady's reaction to chemicals and I would hazard a guess that most algaecides would also provoke her sensitivity. As one contributor suggested algae can be manually removed by suctioning the surfaces with a pool vacuum.

Prior to the acceptance of algaecides as partial remediation for pool maintenance pools were periodically drained and washed with a mild solution of Muriatic acid. This was also done to prevent an accumulation of polio viruses which at that time, were thought to be more prevalent in swimming pools.

UV sterilization, and as other contributors have suggested, Ozone infusion are the least chemically polluting methods of diminishing or eliminating any dermal aggravants from the pool water. Adding chemicals, no matter how benign, may cause other adverse reactions in dermally sensitive persons.

Great point, but rereading the challenge puzzle it states, "She was unaffected by very low levels of the chemicals, but these would only clarify and adjust pH while leaving the algae and parasites alive. How can Tomas kill the algae and parasites and keep the pool clean without giving Juanita a rash?"

That is why the salt water system comes to mind. The residual Hypochlorous acid is very low and deals with both sanitation and algae in one shot.

Not a perfect solution, but there isn't a perfect solution out there, except a good Boddingtons ale, which I would not waste by filling a pool with it. So if you pardon me, I will have one as an evening drink. ;-)

Yes use Poolsan...

Hendrik has the answer. Put an ozone generator on it.

I think he needs to install big heating elements and boil the pool every week.

If the water is heated up to 100°C for one hour, all bacteria will be killed.

Of course, he will lose some of the water by evaporation, but that is a small price to pay for a clean pool.

As regards the algae, he can get rid of those with the suction cleaner.

"I think he needs to install big heating elements and boil the pool every week.

If the water is heated up to 100°C for one hour, all bacteria will be killed.

Of course, he will lose some of the water by evaporation, but that is a small price to pay for a clean pool."

This is really the weirdest solution I could find on the blog. Let's make a small calculation:

Let us assume that we have a nice swimming pool with dimension 7m X 3.5m X 1.5m = 36,75m³ of water.

Heating up all this amount of water from swimmingtemperature of 28°C to 100°C every week will require

36750 kg water X 72° X 4,196 kJ/kgK = 11 102,616 MJ of energy every week. This is an equivalent of the energy required for heating at least 10 houses for a whole year.

Knowing actual prices for energy sources as oil, gas or electrical energy, I certainly would not talk about 'a small price'.

second consideration to be maid is that once the water has a temperature of 100°C, you can no longer use your pool and you have to cool down again the water.

I follow more the opinion about ozone or the salt solution. They are both reliable and affordable solutions to reduce chlorineconentrations in the water

I can't imagine the cost of heating 20,0000 gallons of water every night and then cooling it to a comfortable 85°F (30°C) for normal swimming during the day.

Also, there goes those late night private dips we like to enjoy!

I have solar heating and in the winter it runs full tilt just to get the water to 75°F - 80°F on sunny days in January. I just checked the temperature yesterday evening and it peaked at 83°F. Ready to start swimming again!

Guys, GUYS! (Guest and AH) Come on! I think "tradestar" meant the suggestion as a joke, and you guys took the bait! He is probably laughing at you right now!

Hmmm.....I wonder what the effect of running an uninsulated high voltage cable through the water would be. Might it kill the bacteria and algae or at least provide an inhospitable environment to prevent their growth?

Hmmmmmm......

You could install motion sensors around the pool that cut off the current when humans or pets were around. However, with an appropriate sensitivity, insects would not trigger the cut-off and you could have a great bug-zapper as a bonus!

"Guys, GUYS! (Guest and AH) Come on! I think "tradestar" meant the suggestion as a joke, and you guys took the bait! He is probably laughing at you right now!"

Well, at least I am providing some good amusement, so I am happy to bring some, even at my own expense. ;-))))

Go with Hendrik on ozone sterilized pool, or go with Tom.. on the natural one. The first one is the KISS solution, particularly with an aereator added to flush out remaining ozone, the second one is the real McCoy, but tricky, if some pathogen gets past your attention. It is your skin...

To get back to ozone. It is a great bacteria killer, and fortunately decays quickly.

It however a pollutant at large concentrations.

The following link is one to be found on the net:=

http://www.p2000.umich.edu/recreational/r3.htm

Ozone can be produced by ultraviolet or corona discharge and more.

I think it can be used but the production of bromate should be monitored.

Looks like all solutions have drawbacks!

What a wonderful group of informed responses. Check out www.halopure.com I just completed a test using a combination of their products to clean an industrial water mix. The effluent was Vibratory deburring discharge with high concentrations of ceramic and steel. After just 10 passes through a pressure filter, I could drink the water. They are very close to receiving US EPA approval on the product group I tested. It is already being used in India. They have a patented process where they capture chlorine in small polystyrene beads. The chlorine reacts to organics on contact, never releasing into the fluid stream. I combined that product with their Chitosan flocculant to achieve my results. I have never seen this level of efficacy on this particular discharge. We will be implementing the process soon on site. I suspect cleaning a pool would be relatively easy.

Install an AZONE generator.

http://www.parpool-spa.com/Page/PoolCare/Nature2_Natural_Pool_Purifiers.html

http://www.parpool-spa.com/Page/PoolCare/BioGuard_Optimizer_Plus.html

Check these two sites out. My wife is sensitive to chlorine and won't even go into a hotel pool where chlorine levels are actually unheathly in my opinion. We have about five years experience with Optimizer Plus and two years with the Nature 2 purifier at our home in Northern IL (we can have very hot periods, too.) Since we need a new liner, we have experienced the pool both with and without optimial level of Optimizer Plus (OP). We added OP once five years ago. With the recommended quanity (for our 20,000 gallon pool) the pool water is very stable, doesn't seem to bounce around Ph wise, and the water feels great, stays clean, looks good, etc. Last summer, we used more water due to our liner needing replacement, and as a result OP levels dropped to around 25% of recommended amount. We had lots of problems keeping the pool from turning green, etc., but we resisted adding more OP since we plan to replace the liner this spring. We can't wait to add OP, it works so well. As for the Nature 2 sanitizer, we experience less chlorine and sanitizer needed to maintain a balanced pool. We really like both products (my wife especially appreciated OP). You might want to try these two products.

Tomas could stock the pond with algae eating snails, or even shrimps. The numbers can be controlled with a regular pool-side BBQ. Whatever he does, Juanita will change sex if the last question is anything to go by.

Use OZONE to purify the pool water. Economical ozone generators combined with ultra-violet light purifiers work well for private pools which have limited pathogenic agent contamination potential.

'Public' pools which may have large numbers and high peak load contamination risk need a residual sanitizer (chlorine or bromine) in the water to insure sanitary status is maintained.

Draw a slipstream (does he use a recirc pump ?), add the appropriate concentration of chemicals to do he job and return the slipstream to the pool. Dilution should ensure the daughter does not develop an allergic reaction.

Bhima

Just drain the pool and walk away. Pools are a pain to mess with.

Little Juanita should smear with mineral oil before swimming, as a moisture barrier! *NOT* OK Sorry!

Why couldn't this thread come out last week? I really really need a lowest TCO solution as I'm shopping for 45X pools...

Anyone have a reliable & cost effective solution *before* I commit to 45 new pool filters & supporting systems?

Posting is fine or if you prefer confidentiality -- inventhelp [at] stxvi [dot] com

Thanks!

During WWII, England and the US provided troops in certain locals where obtaining good water could be problematic, small hand pumped filters with diatomaceous earth cartridges embedded with particulate silver, that were so effective that with one pass even raw sewage water could be rendered safe, and clear for drinking. These types of filters are still available for drinking water, and larger scale filtration.

Actually these filters are still widely available. They are sold at any sporting goods store, for avid hikers who go deep out into the natural spaces where no processed water sources are available.

go to the following 'url' are read about silver ion disinfection power and utilization. No more chlorine needed its obsolete and ineffective by comparison

http://www.silverinstitute.org/news/4d1997.htm

You beat me to it. score 1 from me.

Brad

There are many many ways to do this

Ozone would certinly work but is expensive as you need pure oxygen and lots of electricity to produce it.

UV light with peroxide as an oxidizer is very efective and not as expensive.but would the peroxide bother her?

there is also a way to mix chlorine with ammonia to come up with chloramines that may not bother her skin since the chlorine are bound to the ammonia and last longer than free chlorine and is more stable

Mix chlorine and ammonia??? You're dangerous!

Mix chlorine and ammonia??? You're dangerous!

Agreed! Here is why:

http://www.bbc.co.uk/dna/h2g2/classic/A795611

mixing chlorine and ammonia happens every day at most larg water systems

NH₂Cl is commonly used in low concentrations as a disinfectant in municipal water systems as an alternative to chlorination. This application is increasing. Chlorine (sometimes referred to as Free Chlorine) is being displaced by chloramine, which is much more stable and does not dissipate from the water before it reaches consumers.

So-called chlorine intolerance or allergy is quite commonly an allergy to Chloramines rather than the Chlorine itself. Here is an extract from the Wikipedia reference you cited; it's from the section headed "Situations where NH₂Cl should be removed"

"Chloramines, compared to free chlorine, are both less effective as a sanitizer and more irritating to the eyes of swimmers. When swimmers complain of eye irritation from "too much chlorine" in a pool, the problem is typically a high level of chloramines, caused by too little chlorine in relation to the amount of organic matter."

mixing chlorine and ammonia happens every day at most larg water systems

The difference, my dear Guest, is that in the one case you have a controlled chemical process being carried out very carefully by trained, experienced, technical personnel in a closed system where the results are carefully checked and rechecked before the product is released to the public through a distribution system that keeps it free from contamination.

In the other case you have an untrained, non-technical homeowner, often distracted, rarely reading instructions or heeding warnings, typically dumping chemicals first and checking later to see if results are anything close to what he was trying to attain. Not a good way to mix chemicals which have potentially dangerous or hazardous products, especially when protective gear and safety equipment is not available.

IN ELEMENTARY SCHOOL WE WERE INSTRUCTED NEVER TO MIX CHLORINE AND AMMONIA. DOESN'T THE MIX EQUAL MUSTARD GAS?

UV light

For algae and parasites, a UV sterilization system should work.

not an engineer or anything , but isnt there a way to take the pool water and outside the pool run it through a cultured natural marine biological environment, simple fishtank with lots of snails and things that keep water bacteria out, then put it back through a natural medium on its return path back to the pool.

obviously there is a large body of water but arent there natural biological things that just keep on eating the smaller things than themselves that could be used.

I know it works in a fishtank, perhaps also create a sacraficial anode type environment so to speak within the pool to make it more worthwhile the stuff that you kill with chlorine to live in a quarantined area so to speak, and then draw from there the waqter that gets to the outside living bacteria controlling environment.

A put and take system could be used whereby the water is drawn out low, heated via solar technology as it rises through the environment and then at its warmest, tapped off and gravity fed back through a cooling environment somewhat like a still at which point it could enter the pool.

You all might think I have too much time to think and my lack of knowledge reflects but some of the brightest ideas in the world happened from people extracting parts of far fetched ideas and combining them.

any comments, just email deadroo243@yahoo.com.

Ozone is radical oxygen that just loves to "combust" organics. Ceramic plates made of anatase (TiO2) are photoconductive and serve as electrodes in some ozone generators, avoiding metals reactions with the water and current. Anatase is also known to enhance cleanup of biological molecules in air or water in the presence of UV light at a rate that is 10,000x times greater than UV alone. UV light on anatase dissociates water to H and OH radicals that reduce organics to carbon and water.

So we have two possible ways to clean a pool withut chlorine 1) generation of ozone using commercially available ceramic plate generators and 2) the use of anatase coated solar or LED illuminated plates (which also could be used to generate ozone if current were applied).

By putting a small electric current through two copper electrodes thus putting copper ions in the water which the bugs don't like. small breif but to the point.

Regards Brendan

Have you noticed the price of copper recently!!

Just change the water every day,

DO what they do around here, damn up a river, it turns into a pool with an overflow over the dam.

Water stays clean, people like water, viola,

Either that or go to a beach, I prefer Florida Keys

Ozone injection.

Tomas needs to install a ozone generator and blow ozone through a diffuser into the pool water, a simple and cost effective solution adding great health benefits.

High,

RE: CLEANING THE POOL

I understand that many modern pools use Ozone as a disinfectant.

Our local pool does and seems to be clear of infections.

I have not gotten involved in the details of the process - after all I just swim there!

I believe that Chlorine is used downstream to clear the outflow?

Sleepy

The obvious answer is to use an ultra violet irradiation cell after the filter, which destroys some of the unwanted matter. However, less well known and much more effective is to pass the return water through an ultrasonic cell which destroys the bacteria and algae much more thoroughly.

When I was a boy we used to leave a inflated car inner tube in the small farm reservoir( (also used for swimming). It did control the algae to some extend. The tube also provided a relaxing seat.

Where I stay we have saturated dolomite water. The Ph is over 12 and the calcium carbonate is about 300 ppm. Pools turn from clear to an ugly green in minutes at the hint of an electric storm. Most of the proposed methods won't really work properly here. The girl won't last here, thats for sure.

Over here it would be best to immunize her against the allergens.

I would put a pump in the water and shoot the water into the air thus oxiginating the water and cleaning it of any impurities

Bill

My first response, so please be gentle.

Everyone seems focussed on killing the bugs (My vote is for UV light treatment). What about the filtering to remove the organic residue (from the algae and such) to stop that becoming nutrient for later life cycles?

In Australia we use "creepy crawley" devices that run from the filter suction and scrub the pool walls while no-one is around. The water is filtered through sand, activated charcoal or diatomacious filter materials.

Seems to work here

Welcome to CR4!

Not a bad plan. The UV and ozone techniques are valid ways to oxidize the pool water (albeit a bit expensive on electricity). The wall scrubbers probably do a good job at keeping the algae at bay on the walls and floor, which is a weak spot for the UV and ozone generators.

I don't know what would be involved with filtration at that level.

If you want to stick to chemical treatment of the water, you could dose the pool at night (after sundown) with liquid chlorine bleach. By noon of the following day, the sun would have dissipated most of it. This should be OK for the little girl to swim in. If you start with good water and follow a good water maintenance plan, you should be able to have good, clean and sanitary water using less chlorine than found in a municipal water supply (and we drink that!) I do think that it is necessary to shock the pool water once a week (with a larger dose of chlorine) to eliminate any "bugs" that may be building a resistance to the low chlorine concentration.

ozone, uv, sand filter

Although previously mentioned, silver and possibly copper ions are particularly good at keeping bugs down in water, whilst only being present in parts per million concentration.

The following link is to a suppplier of such a pool system:

https://www.aquamatics.com.au/

There are water filters using silver for making drinking water from tap water, showing how harmless silver is when in minute concentration.

However the above answer seemed obvious, and not a challenge, and so I will put on my thinking cap to come up with an answer or 2 from outside the square.

One is don't let Juanita swim!!!!!

The other is use the minimum of chlorine to effectively dose the pool and filter the water with activated carbon.

You may be interested in this link: H2O2

Not the panacea that I was hoping it would be in hot environments where I live. That and it is not approved as a stand alone treatment because compared to chlorine (or ozone, chlorine dioxide, or uv-light), H2O2 is a rather poor disinfectant. So you need to use it as a supliment.

On the plus side, H2O2 does break down chlorine, so shock treatments would be rapidly dissipated.

"H2O2 does break down chlorine". Does that help?
[Presumably the end by-product is a pair of Chlorine ions? Wouldn't this stay in the water and be a more reactive form of chlorine?]

The option for using Ultra Violet light is a known solution for algae in ponds, I have been successfully using a UV filter for many years in my Koi carp pond. This is also thought to kill some bacteria and parasites although I don't think you could rely on it to kill all the bacteria and parasites so perhaps some additional measures would be needed. The Koi are still susceptible to bacteria and parasites probably because the UV filter is inline with the pump and only ensures that the returned water is treated, if there are any dead spots where there is poor water circulation then this water would not get treated to the same level and thus allow parasites and bacteria to survive. The difference is quite amazing, the pond can go from only being able to see 5 or 6 inches down to crystal clear (see the bottom 5 feet down) in about 3-5 days. These are cheap to run as they only use a few watts of electricity. They can affect the PH as the algae dies and this may need to be checked.

Easy.

Convert the pool to salt water.

UV light sanitizer in the intake to the filter. May have to increase pump and filter to better handle the turn over of the water. Or separate the sanitizer. Aerating the water will help also.