How to Eliminate Algae in Outdoor Swimming Pools

Are you on commission?

Nope, just thought is was interesting technology, took about a minute and a half to find it with Google.

I don't own a pool or know much about pool care....L8R..........

Dear Marker

I'm too much sorry , I don't Know how to express you my big apologize , may you misunderstand me while I'm pointing for our chemical company , I never mean you.

by the way i visit the web site which you advised me,i find it too much useful it gives me more and more knowledges about my problem ,i advise this web for all colleagues which may interesting to swimming pools.

thank you for your advise ,again i hope to accept my regret,can i hear OK ?

Everybody has bagged you Markar, but I believe you are correct. I live in Australia and have a "Genius" filter attached to my system and it does everything you claim for the "pool wizard". Sure, it isn't as cheap as a chlorine only system but a lot easier and more effective for me, and I work such fierce houirs that regular maintennance is not an option. I am very happy with the performance of this system in my pool.

Cheers,

Pete.

Amen and a GA. Have had pools in a subtropical climate for 30 years and have tried most of the gadgets - always returned to the good old Chlorine (HTH as a brand in SA). As you say, if you test for and control on a weekly basis the alkalinity, total alkalinity, PH and chlorine levels you will have a clean pool, children with their own coloured hair, no ear infections etc and a sparkling blue pool.

(Thinking about it I think I will go and check it - or better still swim in it).

I agree with this. In addition a good backwash at least once a week and when the return water flow is low. Keep the traps clear of debris as often as possible to keep flow as high as possible.

My kids get sparkling water every weekend!!

GA.

I would add that removing flotsam and jetsam and bottom debris quickly is also very important.

Algae needs food to grow.

what,s for Copper sulphate in powder form, is it suitable as Copper fungicide ?

If yes what is suitable Dosing ? if our pool is 700 CU. M

For more information ,I'm in Saudi Arabia where a hot climate and strong sun light

I am not well versed on its use. I know it is very, very strong, some experts advise against its use in home pools, can stain a pool green, give swimmers green hair, and be a general nuisance.

However, your climate may demand it. I would check with local pool experts to get their opinion on its use.

In Florida we use a copper algaecide in liquid form and pour it in once every 2 or 3 weeks during the peak bathing season (Spring through Fall). I don't use much and as long as chlorine, alkalinity, and pH are stable we have little problems with algae growth.

During the winter months we back off on chlorine and chemicals since the pool is not used much at all, but its time to get into the regiment again as temperatures here are back into the 80°F range.

Only use it if you want green hair.

GA - Have tried everything that comes along for years, but proper cleaning, PH balance and chlorine concentration is the only consistent preformer.

Hello there.

There's "salt" you can buy and turn your swimming pool into salt water.

No bacteria, no harm to the environment.

Look around you will find it.

It ain't that easy.

I like salt systems. My neighbor uses one and likes it. He uses about 400 pounds of salt per year and you need some kind of stabilizer additive. Initial investment is high, but overall operational cost is a little lower. About every 3 years you need to replace the generator element. Cost is about $350.

The downside to a salt system is you must constantly attend to the pool's pH and keep it between 7.2 and 7.8. I think you must continually add acid as the pool pH always rises as part of the chemistry of a salt system.

There is nominal wear and tear on the pool from corrosion, but this is mostly if you get a runaway condition where you generate a lot of chlorine. Salt systems are not good for water falls, which we have.

Fill it in. Plant a garden.

try with algae eating fish. let them swim in the pool from time to time, before being fed..

I find ozone works, without a whole lot of chemistry, overdosing and other maintenance problems encountered with trying to maintain proper chemistry in the pool.

Ozone is an excellent oxidizer, which is what chlorine, UV, hydrogen peroxide, and other chemicals do and leaves no trace chemicals.

The problem with ozone is that it will do nothing for algae growth on the pool walls and you must regularly use additional chemicals (i.e., chlorine and copper) to keep the algae in check.

The reason that ozone is useless for controlling algae growth on pool walls and floors is because ozone is generated at a point source (not homogonous within the pool) the ozone only kills what passes through its point source. Ozone breaks down very, very rapidly from the moment it leaves the ozone generator and never makes it into the main pool.

Here in Alabama USA, we use a bromine based sanitizer and a chemical algecide. Works great we only have to mess with chemicals once a month, they cost around 1/2 the price of chlorine sanitizers. We have strong sunlight problems too. Maybe not as bad as Saudi Arabia but hot enough... Your pool supply store can test your water for you usually free and guide you on how to handle any problems. Make friends with them, they are a very useful resource. Probably can't do that on line, go see them and talk to them. (By the way throw your test kit away and buy a new fresh one, they go out of date fairly quickly and the chemicals loose their pizazz). We have had a pool for 23 years now and have learned to consult the professionals.

You may wandered if you know that we have already a specialist company , they made a regular visit every three month's . each time they advise us with different chemical . finally they dealing with us as a good consumer for their chemicals .They didn't gave any advice , only new chemicals , more costs but no improvement.

So why I ask engineering web colleagues , may some one has more experience without any personal utility

KAIRY AISH,

I would like to share my experience in handling algae growth prevention in open pond or tanks .I have an open over head water tank [uncovered at top],in which massive growth of green algae development was noted periodically, inspite of brushing and cleaning once in a month.Wheresa my neighbour was found very comfortable without algae development issues and frequent cleaning work. The neighbour house madam, saw me every time cleaning the tank with lots of hardships and suggested her valuable common sense advice, which worked magically. She told me 'Sir you have to close the top of your tank and prevent it from sunlight exposure.

*Immediately it struck me that, she means the right thing ,because-open sunlight exposure to water tanks/pools helps algae growth by facilitating PHOTOSYSTHESIS reaction by which enormous algae growth is feasible. Hence sunlight prevention by top and side screen work is very important. You may go for artificial light in case of requirement.

*The second part is, coating bottom of tank by light reflective water proof white paint or white tiles work, to prevent U.V LIGHT ABSORBTION.

*To prevent algae, mild chlorination by bleaching powder/sodium hypochlorite periodically will chemically inhibit algae growth and stinking of stagnant water by organic/bacterial decay can be avoided.

Chlorine being a potential air pollutant, now a days combined chlorine and ozonation systems are available for swimming pool services.

Based on your budget you may proceed with the remedies.

Sir,

In pools sanitized with chlorine (in one form or another), its loss is primarily to the air. the following things all increase the loss (wind, splashing, increased water temperature, sunlight, usage by bathers). Keeping the chlorine level in the desired range of 0.5-2.0 ppm really requires testing the water at least three times each day (morning, mid-afternoon and early evening). An automatic feeder of chlorine is most helpful. It can be adjusted up or down, based on your experience and the test results. After a few weeks, you will be able to anticipate the feed rate needed to maintain the chlorine level in the desired range from one test time to another.

Anyone who tests once a day or less often, is going to have blooms of algae in the pool. When they occur, the amount of chemicals you have to add to eliminate the bloom can be very large. If the chlorine level goes too low for a portion of each day, you probably will get an algae bloom after a few weeks, even though it is in range the rest of the time.

I have seen stubborn strains of algae infect a pool and its plaster walls; ones that were resistant even to scrubbing with chlorine bleach and blasting with water from a pressure washer. Hopefully, you will not go there.

Document your test results; keep a log of chemical feed settings, weather, filter status, pressures in the circulation system, etc. All this will help you to manage the pool water chemistry in a way that is least expensive and best. Maintaining a pool, particularly in a warm or hot climate, can be fairly time-consuming. However, the benefits are very real also.

--JMM

Well, I beg to differ with you. I think testing the water three times a day is excessive, unless this is a public pool. Even daily is not required for the average pool owner. There simply is no reason to micromanage chlorine levels to that extent because chlorine levels change dynamically through the day. You will simply be chasing your tail.

From my experience the biggest problem I have encountered is maintaining alkalinity and correct pH levels. Chlorine does not work effectively when the total alkalinity is outside the normal range of 80 to 120 ppm.

When your total alkalinity is screwed you will have a hard time managing your pool pH. Your chlorine levels may check normal or even high under these conditions, but your chlorine will actually be depleted and the test is measuring chloromines, which is why you get a burning sensation and smell chlorine when you swim.

That is why I suggested that the first thing the original poster should do is test total alkalinity and pool pH. I will bet that he is nowhere near the normal level.

If that is true, he should start with a chlorine shock treatment and begin the process of adjusting the total alkalinity back to normal, which must be done slowly and could take a week or two to get it where it belongs.

It takes a little time, but regular testing and keeping the pool chemistry in bounds will go a long way to prevent algae blooms if not eliminate them altogether.

Sir,

As you correctly point out, in public pools, testing three times a day is needed. Indeed, in many cases, testing hourly is required. I suppose part of our difference in opinion is based on an assumption regarding the size of the pool and its normal use. The post does not clarify this.

Chlorine demand changes dramatically each day, because of constant changes in the environment the pool is in and use of the pool. The ideal condition for a pool is to keep the chlorine level in its effective range at all times. This minimizes the cost for chemicals and the risk of harboring pathogens or algae in areas of the pool less exposed to normal water circulation. When you say chlorine levels change dynamically through the day, I understand you to be meaning that unless the chlorine feed rate is adjusted to compensate for changes in the rate of loss, the levels will change dynamically (and dramatically) throughout the day. If your experience with your pool is with testing daily or less often, while maintaining good water appearance without algae blooms or excessive chlorine levels, then you are doing pretty well. Until one has that experience and success, the more frequent testing is prudent.

Your comments regarding alkalinity and pH are right on. Alkalinity in the water treatment and pool industries is better known to chemists as the pH buffering capability of the water. (Confusion occurs because a high pH is called "alkaline" or "basic" and a low pH is called "acidic"; the term "alkaline" is easily confused with the very different term "alkalinity".) Unless there is the 80+ ppm of alkalinity present to buffer the changes that can be caused by addition of the chlorine, the pH of water is easily shifted from the nearly neutral ideal in pools (the pH shift may be either up or down depending on the particular chlorine-containing chemical used). Having an alkalinity larger than 120 ppm is not particularly harmful; indeed, for concrete/plaster pools it is often kept closer to 200 ppm. In my experience, once the alkalinity has been adjusted to its desired range, it is fairly stable and needs further correction only every 1-3 weeks. Although pool supply companies have name-branded chemicals to increase the alkalinity, it is much less expensive to use sodium bicarbonate (NaHCO₃).

Something neither of us has mentioned up to now is that the chlorine testing needs to be for both free and total chlorine. If they are not nearly equal superchlorination or "shock treatment" is usually required.

--John M.

I sent already a water sample for out side lab to calculate accurately the values of PH and alkalinity .may our manual kit is not accurate enough.

Am i need to adjust alkalinity level before proceeding chlorine chock , what is the advisable level to insure active chlorine effect .

You can start the shock immediately and the amount depends on the volume of your pool. What is the volume?

If you don't know the size of your pool there are pool size calculators available on the web if you do a search.

What has been your treatment plan for your pool to date?

we start by sending water sample for PH and Alkalinity value calculation , i will receive result tomorrow . we checked sand filters and circulation pumps ,they are ok, i found some of leaf traps broken and leafs scape to sand filter , we are in way to change

Now how much chlorine we need to add for chlorine shock if you know that our pool is 700 Cu meter ?

we normally use sodium hypochlorite ( tab) or calcium hypochlorite (powder)

Nice sized pool you have.

Here is a link to help calculate the amount you need to add. Many factors determine your amount of chlorine for a shock treatment as you will read.

We buy shock treatment in premeasured bags. For your pool it would need 2.5 bags as written buy the stuff we buy. The link I gave you is a better way to calculate it and assuming you are an engineer you probably will appreciate knowing the details.

Personally, I buty my shock treatment from WalMart. I get the stuff with a "flocculant" already inside the bag. The flocculant causes any oxidized material that the shock treatment "kills" to clump together and drop to the bottom for easy vacuuming. Flocculant really makes life easier, but you can also buy it in liquid form and add it to your pool independently of chlorine.

I throw in one or two bags in a bucket of HOT water and dump it in the pool. I do this by the "seat of my pants" every week or two at night. I personally don't feel the need to measurebate everything when it comes to pool care. I do check periodically, but it just confirms if I am on track. After a little while you should get a good feel of how your pool runs and when you get it sorted out keeping it running smooth and level is not that hard.

Best of luck and enjoy your pool!

I think now i know will my way . too much thanks for you and all colleagues which shared me this fantastic forum with fantastic group, it guides me for some points which was completely hidden for me. My best wishes and hoping all success for all of yours

khairy aish

Same here. Enjoy your pool, be safe, and have a wonderful summer.