H E L P

[TommyDee]

There are 5 pools here, where I live, and until xmas we had a good gardener/poolman who legged it once he got paid, never to be seen since.

2 pools, while i was away and unaware that he had gone, decided to go cloudy and develop green "algea" on the sides.

I bought potash soda, chlorine and a "kit" for testing water. I scrubbed the walls, left the filters on and have got the chlorine levels up to the right colour on the tester.

No matter how much of this white powder ( potash i think) I add, the water stays cloudy. i did add some CuSO4 as i read somewhere that helps.

after 2 days i had a thick brown deposit on the pool base, which i vacuumed up while on "waste" so the pool wasnt disturbed. it has all gone now.

My problem is that I cant seem to raise the "ph" level no matter how much pottash i add. it remains the yellow colour at the bottom of the tester chart, and the water is NOT clear.

I am new to this, but am determined to understand it. PLEASE HELP thanks in advance

Tommy

[TommyDee]

ps.. if anyone lives near marprachan and fancies a cuppa in exhange for a helping hand, would be more than welcome

[gosompoi]

Bring your PH up!, keep checking your PH, chlorine and keep up the vacuuming. Your half way there! When was the last time you back-washed your sand filters, what is your pressure reading on your sand filters?

[WarpSpeed]

Bring up your total alkalinity first with bicarb and you need a special kit to test it most likely though it's possible your test kit tests it.. Soda ash will do little to raise your pH if your T/A is totally burned off and you also will not get the cloud to settle until it is high enough to coagulate the fallout and make it drop.

Put in small portions at a time, need to know the approximate pool size before it's possible to give a starting point.

By the way if you have a sand filter best to shut the pump off completely for the duration and only treat the pool with chems and waste vacuuming as needed. All sand filters do is stir up the pool in a case like this as the fall out is too small for them to filter efficiently and they get easily saturated which then causes them to bypass the fallout back into the pool..

Edited January 10, 2012 by WarpSpeed

[AllanB]

All this chemical stuff gets me a little worried, what the hell are you going to swimming in and will it solve all the problems permanently? I doubt it algae always returns.

How big are these pools and what is the water supply situation? Why not drain it/them and start again, I have a 40m3 pool and an average water flow of 1.1m3/hour, so a drain and refill takes about 2 days and costs about 500baht. You have solved the problem permanently then, if the water supply is not good, filter it first.

If you do make sure you take the appropriate precautions to prevent lift.

[TommyDee]

Bring your PH up!, keep checking your PH, chlorine and keep up the vacuuming. Your half way there! When was the last time you back-washed your sand filters, what is your pressure reading on your sand filters?

thanks. I didnt know about baking soda tho??? I backwash the filters every day at the moment and when I vacuum i do it on "waste" so it by passes the filter, then backwash it and rinse. the PH is so low its nearly off the scale and I think, fro here, that I have been adding too much potash at one time. the green pools are turning clear-ish again but not crystal by any means. I guess once it gets right it is easy t maintain the levels

[monsieurhappy]

I think you are trying to do "too much, too quickly" if you can understand where I'm coming from.

Backwashing should only be done about once a month and only if there's indication the pool is in need of backwashing. Keep an eye on the pressure gauge on the sand filter, there's usually a mark or a coloured area that indicates b/wash is needed.

It's a good idea to vacuum to to waste but only when there is a lot of crud laying on the bottom of the pool.

I would tackle the algae problem first. After vacuuming, give the walls of the pool a brush down if there's any algae sticking to them. Then add some extra chlorine. For a pool about 80,000 litres I would add about 1 kilo of chlorine granules. Set the pump for 2x 3 hour sessions and leave for a couple of days. If no more algae has started to grow around the pool you can go on with the treatment. If algae is again growing or if test kit indicates chlorine low,then add more chlorine but remember a little at a time. Check the ph. and if low add about a kilo of soda ash ( mix in bucket with water before adding to pool ) Don't add too much too soon, if still low add same next day. I've found that some brands of soda ash ( may even be the chemical for testing ph. ) don't always give the same colour indication on testing kit so I use colour nearest without going over. When I first started cleaning my own pool I made the mistake of adding too much soda ash too quickly and found the water went very cloudy!

Before anyone criticises my method, let me just say I'm NOT an expert but have been cleaning my own pool for the last 5-6 years. I've learnt a lot, mainly the hard way. After a while cleaning becomes less hard and less time consuming, just keep an eye on things and do what's needed WHEN it's needed!

Hope that helps.

Edited January 12, 2012 by monsieurhappy

[AllanB]

I am still convinced that draining, cleaning and refilling to pool is the best solution, but it seems I am in a minority, so here is an important point if you don't,

Algae reoccurrences happen in a swimming pool because the algae was not completely eradicated when treated. Sometimes poor or misdirected water circulation can prevent the pool chemicals from removing all of the algae.

When treating a swim pool for algae, it is important that all parts of the pool receive a dose of algaecide. Some of the many types of algae can exist outside the pool and will reinfest the water when brought back in contact with the water. An excellent example of this is yellow, commonly called mustard, algae. These spores can survive outside the water for extended periods of time. It is important that when you treat for algae you submerge your cleaning equipment in the pool overnight, so that the algae on them is killed also. If you don't take this precaution, the next time you vacuum or skim for leaves you may reinfest your pool with algae spores.

[Bagwain]

I am out that way a fare bit and my business is trouble shooting pools and water filtration in general.

Busy at the moment but I may get out that way in the next day or so.

PM me with your phone number and we can chat.

Cheers

[monsieurhappy]

I am still convinced that draining, cleaning and refilling to pool is the best solution, but it seems I am in a minority, so here is an important point if you don't,

Algae reoccurrences happen in a swimming pool because the algae was not completely eradicated when treated. Sometimes poor or misdirected water circulation can prevent the pool chemicals from removing all of the algae.

When treating a swim pool for algae, it is important that all parts of the pool receive a dose of algaecide. Some of the many types of algae can exist outside the pool and will reinfest the water when brought back in contact with the water. An excellent example of this is yellow, commonly called mustard, algae. These spores can survive outside the water for extended periods of time. It is important that when you treat for algae you submerge your cleaning equipment in the pool overnight, so that the algae on them is killed also. If you don't take this precaution, the next time you vacuum or skim for leaves you may reinfest your pool with algae spores.

In that case you must also empty, clean and refill your sand filter as this would be the best place for algae to remain! I would also like to know from where you obtain your fresh water as this also could be a source for recontamination with algae?

I think you are going over the top with your treatment but everyone to their own. Usually I would say "if it works then go ahead."

[AllanB]

I am still convinced that draining, cleaning and refilling to pool is the best solution, but it seems I am in a minority, so here is an important point if you don't,

Algae reoccurrences happen in a swimming pool because the algae was not completely eradicated when treated. Sometimes poor or misdirected water circulation can prevent the pool chemicals from removing all of the algae.

When treating a swim pool for algae, it is important that all parts of the pool receive a dose of algaecide. Some of the many types of algae can exist outside the pool and will reinfest the water when brought back in contact with the water. An excellent example of this is yellow, commonly called mustard, algae. These spores can survive outside the water for extended periods of time. It is important that when you treat for algae you submerge your cleaning equipment in the pool overnight, so that the algae on them is killed also. If you don't take this precaution, the next time you vacuum or skim for leaves you may reinfest your pool with algae spores.

In that case you must also empty, clean and refill your sand filter as this would be the best place for algae to remain! I would also like to know from where you obtain your fresh water as this also could be a source for recontamination with algae?

I think you are going over the top with your treatment but everyone to their own. Usually I would say "if it works then go ahead."

Yet another problem with sand filters, a great breeding ground, impossible to inspect, difficult to clean..

[gosompoi]

Bring your PH up!, keep checking your PH, chlorine and keep up the vacuuming. Your half way there! When was the last time you back-washed your sand filters, what is your pressure reading on your sand filters?

thanks. I didnt know about baking soda tho??? I backwash the filters every day at the moment and when I vacuum i do it on "waste" so it by passes the filter, then backwash it and rinse. the PH is so low its nearly off the scale and I think, fro here, that I have been adding too much potash at one time. the green pools are turning clear-ish again but not crystal by any means. I guess once it gets right it is easy t maintain the levels

You do not need to backwash the filter everyday during this problem period. It is better for the working of the sand filter if you do not backwash everyday, watch the pressure gauge. You are on the right path and doing the right things. Your problem is your PH, I would also check your Total alkalinity and add sodium bicarbonate.

Edited January 13, 2012 by gosompoi

[TommyDee]

I am out that way a fare bit and my business is trouble shooting pools and water filtration in general.

Busy at the moment but I may get out that way in the next day or so.

PM me with your phone number and we can chat.

Cheers

thanks for calling by and for the tips, i am out shopping for the final powder tomorrow. very helpful indeed I learned a lot from our chat, and the few glasses of wine made the afternoon even better

[canda]

I am still convinced that draining, cleaning and refilling to pool is the best solution, but it seems I am in a minority, so here is an important point if you don't,

Algae reoccurrences happen in a swimming pool because the algae was not completely eradicated when treated. Sometimes poor or misdirected water circulation can prevent the pool chemicals from removing all of the algae.

When treating a swim pool for algae, it is important that all parts of the pool receive a dose of algaecide. Some of the many types of algae can exist outside the pool and will reinfest the water when brought back in contact with the water. An excellent example of this is yellow, commonly called mustard, algae. These spores can survive outside the water for extended periods of time. It is important that when you treat for algae you submerge your cleaning equipment in the pool overnight, so that the algae on them is killed also. If you don't take this precaution, the next time you vacuum or skim for leaves you may reinfest your pool with algae spores.

In that case you must also empty, clean and refill your sand filter as this would be the best place for algae to remain! I would also like to know from where you obtain your fresh water as this also could be a source for recontamination with algae?

I think you are going over the top with your treatment but everyone to their own. Usually I would say "if it works then go ahead."

Yet another problem with sand filters, a great breeding ground, impossible to inspect, difficult to clean..

For all those folk having issues with sand filtration, do yourselves a huge favour and change to one of the new medias available, we, and now, many of our friends have changed to glass media and never looked back, reduced algae growth, no channeling, less backwashing, better clarity, etc, etc,. Our sand media was due to be changed after about 4 years of daily filtration, so for a couple of thousand baht more we changed to glass, from what I've heard the life expectancy is more than twice that of sand and the grade of sand used here in Thailand isn't as high a standard as many other countries. As we have bore water, we were also occasionally having issues with reactive iron deposits discolouring the water, now, almost two years after the change - over we haven't had a problem there either.

CANDA

[curtklay]

Your PH will not stabilize until you raise the TOTAL ALKALINITY to 100-120 ppm. You do this with Sodium Bicarbonate (Baking Soda). Then if the PH is still low, you can raise it with Soda Ash. Get a good 4 in 1 test kit that checks PH (red reagent) and Total Alkalinity (blue reagent). Once balance is stable, shock the hell out of it with chlorine to kill the algae. The chlorine test should turn very dark yellow. Run the filter 24 hours and keep the chlorine high until the water clears. An algaecide may be needed if the algae has gotten far out of control. Clean the filter after the water clears. The alkalinity test should be done regularly. When the alkalinity drops too low, the PH bounces around and the chlorine becomes ineffective. There should be no need to drain the pool.

Edited January 17, 2012 by curtklay

[stevehaigh]

I am still convinced that draining, cleaning and refilling to pool is the best solution, but it seems I am in a minority, so here is an important point if you don't,

i would agree if water cost not a big issue

then he can wash the empty pool with concentrated chlorine to get algae off the tile surface and the grout otherwise its going to come back anyhow

[TommyDee]

just as an update. I am not "out of the water" yet but after scrubbing the walls while in the bloody water, adding baking soda, vacuuming2-3 times a week, ( on waste not recycle), the water is very very clear. the PH is nearly up in the right area and Cl is OK. the local "experts" had simply been adding acid without checking the PH so we had some way to go. Having backflushed and rinsed several times now the pressure is good and hope to see it glistening soon. In any event it will be emptied in the next few months to replace the ruined top two layers of tiles and install another jet as I am informed we have to few jets for the pool ( for filtering). Many thx for the hlep received her and also a visit which helped.

tommy

[PoolDoctor]

A tiny bit of cheap clarifier works wonders well too, once alkalinity, pH and ORP are in range. Cloudy water is almost [...] always a filtration problem, but algae is a chemistry problem.

[TommyDee]

A tiny bit of cheap clarifier works wonders well too, once alkalinity, pH and ORP are in range. Cloudy water is almost [...] always a filtration problem, but algae is a chemistry problem.

when I finished standing in it and scrubbing the walls, the water was pea soup. thick as soup too. in the last two weeks it has been treated and vaccumed semi daily, backwashed and rinsed and now.. is crystal clear. at one tie I thought it was beyond me, but there it is. just needs some cosmetic work and all will be perfect

[AllanB]

A tiny bit of cheap clarifier works wonders well too, once alkalinity, pH and ORP are in range. Cloudy water is almost [...] always a filtration problem, but algae is a chemistry problem.

when I finished standing in it and scrubbing the walls, the water was pea soup. thick as soup too. in the last two weeks it has been treated and vaccumed semi daily, backwashed and rinsed and now.. is crystal clear. at one tie I thought it was beyond me, but there it is. just needs some cosmetic work and all will be perfect

My goodness you are a brave man, standing in filthy water scrubbing a swimming pool, reminds me of the Shawshank Redemption. I fear the pool will be perfect for a couple of days only and you will be fighting a rear guard action forever, so buy a lot of chlorine, etc. If you have 4 more pools to do in the same way, I fear for your health.

On the estate where I live the builder built a beautiful "overflow" communal pool, with sand filteration, which was clean and lovely to swim in for a few months and then it went green. He tried a clean up job and each time the water was clear for a few days, but the taste was not good and no one would swim in it and it went green again. He got so sick of constantly shocking the thing at his expense, that he left it and it went very green and thick with algae, a home for amphibians.

Last new year he held a party there and decided to do a clean up job, drained and refilled the pool. I told him he should replace the sand in the filter and bleach the whole thing out, but he said it was unnecessary. The pool was clean for about 3 weeks and then the green returned and he began shocking again. He then gave up and the pool is now a wreck.

I do not have "25 years experience in the business", but logic tells me decontamination is the best answer.

I would add that algae is a filtration problem and the chemical solution is not your best answer, or most cost effective answer.

[WarpSpeed]

I am still convinced that draining, cleaning and refilling to pool is the best solution, but it seems I am in a minority, so here is an important point if you don't,

i would agree if water cost not a big issue

then he can wash the empty pool with concentrated chlorine to get algae off the tile surface and the grout otherwise its going to come back anyhow

Over time it's going to come back, it's inevitable and part of having a pool so better to learn to how to deal with it without having to drain it constantly especially here where the water can come from your local pond or well anyways and is even worse then water he's trying to balance now. Moreover if he learns proper chemical balance he'll have fewer problems with it in the first place..

[WarpSpeed]

A tiny bit of cheap clarifier works wonders well too, once alkalinity, pH and ORP are in range. Cloudy water is almost [...] always a filtration problem, but algae is a chemistry problem.

when I finished standing in it and scrubbing the walls, the water was pea soup. thick as soup too. in the last two weeks it has been treated and vaccumed semi daily, backwashed and rinsed and now.. is crystal clear. at one tie I thought it was beyond me, but there it is. just needs some cosmetic work and all will be perfect

Good to hear it, IMO you could have shortened the cleansing time by turning off your filter though, done it that way at least 100 or more times on pools so green you couldn't see the top step and got them crystal blue in less then 2 weeks..

There is no health issues to worry about, I've been in 100's of pools in my bare feet both bleach and acid washing them (the only way to avoid falling on your derriere) (again many as green as ponds not swimming pools) for more then 20 years and no such health effects so that's more drama then anything else.

[WarpSpeed]

A tiny bit of cheap clarifier works wonders well too, once alkalinity, pH and ORP are in range. Cloudy water is almost [...] always a filtration problem, but algae is a chemistry problem.

when I finished standing in it and scrubbing the walls, the water was pea soup. thick as soup too. in the last two weeks it has been treated and vaccumed semi daily, backwashed and rinsed and now.. is crystal clear. at one tie I thought it was beyond me, but there it is. just needs some cosmetic work and all will be perfect

I would add that algae is a filtration problem and the chemical solution is not your best answer, or most cost effective answer.

Algae is singularly a chemical problem, I can keep a pool blue for months without a pump or filter, it won't be crystal clear but it will be plenty clear enough and algae free..

Edited February 4, 2012 by WarpSpeed

[TommyDee]

A tiny bit of cheap clarifier works wonders well too, once alkalinity, pH and ORP are in range. Cloudy water is almost [...] always a filtration problem, but algae is a chemistry problem.

when I finished standing in it and scrubbing the walls, the water was pea soup. thick as soup too. in the last two weeks it has been treated and vaccumed semi daily, backwashed and rinsed and now.. is crystal clear. at one tie I thought it was beyond me, but there it is. just needs some cosmetic work and all will be perfect

My goodness you are a brave man, standing in filthy water scrubbing a swimming pool, reminds me of the Shawshank Redemption. I fear the pool will be perfect for a couple of days only and you will be fighting a rear guard action forever, so buy a lot of chlorine, etc. If you have 4 more pools to do in the same way, I fear for your health.

On the estate where I live the builder built a beautiful "overflow" communal pool, with sand filteration, which was clean and lovely to swim in for a few months and then it went green. He tried a clean up job and each time the water was clear for a few days, but the taste was not good and no one would swim in it and it went green again. He got so sick of constantly shocking the thing at his expense, that he left it and it went very green and thick with algae, a home for amphibians.

Last new year he held a party there and decided to do a clean up job, drained and refilled the pool. I told him he should replace the sand in the filter and bleach the whole thing out, but he said it was unnecessary. The pool was clean for about 3 weeks and then the green returned and he began shocking again. He then gave up and the pool is now a wreck.

I do not have "25 years experience in the business", but logic tells me decontamination is the best answer.

I would add that algae is a filtration problem and the chemical solution is not your best answer, or most cost effective answer.

I am a worker not a shirker so a bit of labour doesnt bother me really. the water was the colour of peas soup by the time I had finished though. the filters and pump were turned off to let the s**t settle on the pool floor,(2 days) and the pool was vacuumed, by me, 3 times a week until last week.

Meanwhile I was advised to invest in baking soda and fought for the same time to remove the acid level which was messed up by the ex pool guys. the change was very slow, from acid to acceptable and I was dis-illusioned to start with as the test i did daily didnt sem to change.

BUT.. the water is now clear, lovely and clear, the walls are fine, the PH and chlorine levels are exactly where they are supposed to be, the pump runs4-5 hours a day, the sand has been backwashed twice a week and finally I am on a normal maintain programme, which involves a weekly or 2x weekly vaccum, depending on the weather, storms wind and crud, daily "viewing" and chem tests 2x a week too.

the tiles are not the best they are cheap ones and really the pool needs to be renovated but to be honest the cost is a bloody nightmare especially if we are to consider saltwater system too. so I think we will plough on as we are and "see".

I truly appreciate the advice I got here, its been invaluable in many ways and the difference of opinion.. very interesting

so far...so good

[AllanB]

A tiny bit of cheap clarifier works wonders well too, once alkalinity, pH and ORP are in range. Cloudy water is almost [...] always a filtration problem, but algae is a chemistry problem.

when I finished standing in it and scrubbing the walls, the water was pea soup. thick as soup too. in the last two weeks it has been treated and vaccumed semi daily, backwashed and rinsed and now.. is crystal clear. at one tie I thought it was beyond me, but there it is. just needs some cosmetic work and all will be perfect

My goodness you are a brave man, standing in filthy water scrubbing a swimming pool, reminds me of the Shawshank Redemption. I fear the pool will be perfect for a couple of days only and you will be fighting a rear guard action forever, so buy a lot of chlorine, etc. If you have 4 more pools to do in the same way, I fear for your health.

On the estate where I live the builder built a beautiful "overflow" communal pool, with sand filteration, which was clean and lovely to swim in for a few months and then it went green. He tried a clean up job and each time the water was clear for a few days, but the taste was not good and no one would swim in it and it went green again. He got so sick of constantly shocking the thing at his expense, that he left it and it went very green and thick with algae, a home for amphibians.

Last new year he held a party there and decided to do a clean up job, drained and refilled the pool. I told him he should replace the sand in the filter and bleach the whole thing out, but he said it was unnecessary. The pool was clean for about 3 weeks and then the green returned and he began shocking again. He then gave up and the pool is now a wreck.

I do not have "25 years experience in the business", but logic tells me decontamination is the best answer.

I would add that algae is a filtration problem and the chemical solution is not your best answer, or most cost effective answer.

I am a worker not a shirker so a bit of labour doesnt bother me really. the water was the colour of peas soup by the time I had finished though. the filters and pump were turned off to let the s**t settle on the pool floor,(2 days) and the pool was vacuumed, by me, 3 times a week until last week.

I wasn't suggesting you were lazy, merely brave, possible fool hardy,

This density of algae is a breeding ground for bacteria and parasites and much of the former can become airborne, when you are in the pool scrubbing and stirring this mess up. So you have two ways of becoming infected, lung infections being much more difficult to treat than any other. This is because antibiotics cant reach inside the lung cavities, hence the reason acute Bronchitis is considered virtually incurable.

That is why I suggested emptying the pool and working in a more manageable environment where you can neutralise the problems as you go. If you have four more pools left you are really pushing your luck and when the weather heats up the risks become greater.

You don't need this experience for the future, just manage the water better and control the algae before it gets a foothold. Which is what you seems to be doing now on this pool.

[WarpSpeed]

A tiny bit of cheap clarifier works wonders well too, once alkalinity, pH and ORP are in range. Cloudy water is almost [...] always a filtration problem, but algae is a chemistry problem.

when I finished standing in it and scrubbing the walls, the water was pea soup. thick as soup too. in the last two weeks it has been treated and vaccumed semi daily, backwashed and rinsed and now.. is crystal clear. at one tie I thought it was beyond me, but there it is. just needs some cosmetic work and all will be perfect

My goodness you are a brave man, standing in filthy water scrubbing a swimming pool, reminds me of the Shawshank Redemption. I fear the pool will be perfect for a couple of days only and you will be fighting a rear guard action forever, so buy a lot of chlorine, etc. If you have 4 more pools to do in the same way, I fear for your health.

On the estate where I live the builder built a beautiful "overflow" communal pool, with sand filteration, which was clean and lovely to swim in for a few months and then it went green. He tried a clean up job and each time the water was clear for a few days, but the taste was not good and no one would swim in it and it went green again. He got so sick of constantly shocking the thing at his expense, that he left it and it went very green and thick with algae, a home for amphibians.

Last new year he held a party there and decided to do a clean up job, drained and refilled the pool. I told him he should replace the sand in the filter and bleach the whole thing out, but he said it was unnecessary. The pool was clean for about 3 weeks and then the green returned and he began shocking again. He then gave up and the pool is now a wreck.

I do not have "25 years experience in the business", but logic tells me decontamination is the best answer.

I would add that algae is a filtration problem and the chemical solution is not your best answer, or most cost effective answer.

I am a worker not a shirker so a bit of labour doesnt bother me really. the water was the colour of peas soup by the time I had finished though. the filters and pump were turned off to let the s**t settle on the pool floor,(2 days) and the pool was vacuumed, by me, 3 times a week until last week.

Meanwhile I was advised to invest in baking soda and fought for the same time to remove the acid level which was messed up by the ex pool guys. the change was very slow, from acid to acceptable and I was dis-illusioned to start with as the test i did daily didnt sem to change.

BUT.. the water is now clear, lovely and clear, the walls are fine, the PH and chlorine levels are exactly where they are supposed to be, the pump runs4-5 hours a day, the sand has been backwashed twice a week and finally I am on a normal maintain programme, which involves a weekly or 2x weekly vaccum, depending on the weather, storms wind and crud, daily "viewing" and chem tests 2x a week too.

the tiles are not the best they are cheap ones and really the pool needs to be renovated but to be honest the cost is a bloody nightmare especially if we are to consider saltwater system too. so I think we will plough on as we are and "see".

I truly appreciate the advice I got here, its been invaluable in many ways and the difference of opinion.. very interesting

so far...so good

Good to hear Tommy so you did actually turn off the pump and let it settle, excellent... Good learning experience for you..

I'd back off on sand filter backwashing though now to every 2 to 3 weeks is plenty and actually beneficial as a sand filter is more efficient when it's a bit dirty and the sand has settled back in place especially the large sand grains used here.

In essence when you backwash you loosen up and reverse water flow through the filter to remove the captured debris so at that point your actually at your worst filtering efficiency with a sand filter for the next several days AFTER backwashing until the sand settles back to be more compact thus closing up the spaces between grains..

The trick is not to override that time frame as once you do achieve dirt saturation then it will begin to bypass or can crush an internal lateral from too much pressure as it can be a rather sudden increase in pressure change at that point. That is a bit rare and mostly a concern on older filters but to be aware of, if you have a PSI gauge that is helpful and should be backwashed after a rise of no more then 5 pounds which usually occurs in the recommended time frame.

[WarpSpeed]

when I finished standing in it and scrubbing the walls, the water was pea soup. thick as soup too. in the last two weeks it has been treated and vaccumed semi daily, backwashed and rinsed and now.. is crystal clear. at one tie I thought it was beyond me, but there it is. just needs some cosmetic work and all will be perfect

My goodness you are a brave man, standing in filthy water scrubbing a swimming pool, reminds me of the Shawshank Redemption. I fear the pool will be perfect for a couple of days only and you will be fighting a rear guard action forever, so buy a lot of chlorine, etc. If you have 4 more pools to do in the same way, I fear for your health.

On the estate where I live the builder built a beautiful "overflow" communal pool, with sand filteration, which was clean and lovely to swim in for a few months and then it went green. He tried a clean up job and each time the water was clear for a few days, but the taste was not good and no one would swim in it and it went green again. He got so sick of constantly shocking the thing at his expense, that he left it and it went very green and thick with algae, a home for amphibians.

Last new year he held a party there and decided to do a clean up job, drained and refilled the pool. I told him he should replace the sand in the filter and bleach the whole thing out, but he said it was unnecessary. The pool was clean for about 3 weeks and then the green returned and he began shocking again. He then gave up and the pool is now a wreck.

I do not have "25 years experience in the business", but logic tells me decontamination is the best answer.

I would add that algae is a filtration problem and the chemical solution is not your best answer, or most cost effective answer.

I am a worker not a shirker so a bit of labour doesnt bother me really. the water was the colour of peas soup by the time I had finished though. the filters and pump were turned off to let the s**t settle on the pool floor,(2 days) and the pool was vacuumed, by me, 3 times a week until last week.

I wasn't suggesting you were lazy, merely brave, possible fool hardy,

This density of algae is a breeding ground for bacteria and parasites and much of the former can become airborne, when you are in the pool scrubbing and stirring this mess up. So you have two ways of becoming infected, lung infections being much more difficult to treat than any other. This is because antibiotics cant reach inside the lung cavities, hence the reason acute Bronchitis is considered virtually incurable.

That is why I suggested emptying the pool and working in a more manageable environment where you can neutralise the problems as you go. If you have four more pools left you are really pushing your luck and when the weather heats up the risks become greater.

You don't need this experience for the future, just manage the water better and control the algae before it gets a foothold. Which is what you seems to be doing now on this pool.

Sorry but that's just more rubbish, algae like any plant feeds off of nitrates and dissolved solids in the water and is actually a natural filter just not one we prefer for our pools. It's an oxygen producing/releasing plant not bacteria, nor does it harbor harmful bacteria it's not a mold which is completely different and can cause harmful effects if the spores are inhaled and besides algae is beneath the water surface so it releases no gases into the air unless you dry it and then bleach it and it then releases a sweet smelling, almost nauseating scent but even still there is no harmful effects from the release either short or long term....

[AllanB]

This is from a man who advocates walking around in bare feet in bleach and acid to stop himself slipping over.

This is one article picked at random on Google and there are 100's of others http://www.servicemagic.com/article.show.Getting-Rid-of-That-Pesky-Pool-Algae.14317.html

.........but of course these people are talking rubbish too.

So folks we can all swim around in green slime in perfect safety..............