Cannot Remove My Brown/Mustard Algae

by Michelle
(Brownsville, Texas)

I have a DE filter. All my levels are good.


I came from the pool store wondering why I have algae with a good chlorine level? They wanted to give me Yellow Out but it says not to put in pools that have chlorine levels above 1 ppm.

In fact I am afraid to shock because my chlorine level is swimming suitable (4ppm). You say to shock till it gets to 10 ppm. Isn't that dangerous to the liner?

Any suggestions? I was gonna wait until the chorline level resides a little before shocking?

Why isn't the chlorine killing the algae?




Thanks for the question Michelle

I'm not a big fan of products that allege to augment a good chlorine shock. When products like Yellow Out are used they can create more of a chlorine demand in the short run.

Yellow Algae

A chlorine shock to the pool is not dangerous to a liner, but it is important in how you add the chlorine to the pool.

For vinyl liners, the best and safest way to add chlorine is to fill a 5 gallon bucket 1/2 way with pool water, then add the chlorine.

Mix it with a PVC pipe or stick, and broadcast it around the perimeter of the pool. Then sweep the bottom and sides to break up any hot spots. Keep the filter running 24/7 and wear long sleeves, pants, goggles, and rubber gloves for protection.

I'd like to have your complete chemical readings:

Chlorine, CYA (cyanuric acid/stabilizer), pH, Alkalinity, Calcium Hardness, and Metals (iron and copper).

It makes troubleshooting much easier and the process of clearing up your pool will go much faster.

You can get this done at your local pool store or use a good test kit.

Pool Water Testing

Water Testing Kit

Without these numbers I'm just guessing at what the problem is.

Your chlorine could be rendered ineffective (or partially) because the CYA (stabilizer) is either too high or low, or the pH is too high. A pH level of 8.0ppm or above and you're only using about 25% of the chlorine.

An easy chlorine test is to test the water at night and record the number. In the morning retest your chlorine level. This should be done as early as convenient, before the sun hits the pool. It should only drop by 1.0ppm. If it drops more, you do have an algae problem that needs to be addressed.

Get me the chemical numbers and I'm sure I can help.

I'm hesitant to tell you to shock right off the bat because if the CYA is too high a partial water change will be needed. It's better to do this first, then shock, as opposed to using alot of chlorine then do a water change. It's a waste of chemicals and money.

To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Yellow Algae" category.

Swimming Pool Questions and Answers

Check back to this post for updates or answers.

Hope this helps and have a great Summer.

Robert

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Mustard Algae Pool Closing

Our community pool for our subdivision has mustard algae. The pool has not been shut down. Does it need to be shut down until the water has cleared and the algae is gone?




Thanks for the question

The answer is yes the pool needs to be shut down. You'll need to take care of the algae and this includes shocking the pool repeatedly until the algae is gone and the pool water is balanced again.

You can send a list of your chemical numbers. I can take a look at them and see what can be done.

Chlorine, CYA (cyanuric acid/stabilizer), pH, Alkalinity, Calcium Hardness, and Metals (iron and copper) and names of any algaecides you may have used along with clarifiers, phosphate removers, and/or flocs.

I hope this has answered your question to your satisfaction.

To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Yellow Algae" category.

Check back to this post for updates or answers.

If you feel your situation is more complex and want immediate assistance (within 24 hrs) you can make a donation of your choice and I'll answer your questions by phone.

Have I helped you find a solution to your pool problems? Did this information help you? Please consider making a donation to help keep this site going. Thank you.









Have a great Summer.

Robert

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High Phosphates And Hard To Remove Yellow Wall Algae

I am having a problem with yellow algae and my Phosphate level is very high. My pool was resurfaced approximately two Months ago with Marsite. Since then the pool has looked good and water clear.

All of a sudden Labor Day weekend we noticed yellow algae on the walls and some on the bottom, the phosphate levels were very high. We have a pool company that services our pool and provides all chemicals.

We have a screen enclosure around the pool and there has been no fertilizer sprayed in our yard. The pool service company is trying to correct the problem and says it's the amount of rain we have had lately.

Everything I can find states the following "WIND-BLOWN DIRT AND ORGANIC DEBRIS CANNOT BE A SIGNIFICANT SOURCE OF PHOSPHATES IN NORMAL POOL WATER BECAUSE THE AMOUNT OF DIRT REQUIRED TO ACHIEVE HIGH LEVELS OF PO4 WOULD BE UNREALISTIC IN NORMAL POOL ENVIRONMENTS.

No one has put anything in the pool except the pool service and I am not wanting to pay for some work to clear up my pool that was caused by the Pool Service.

I know you or I do not know exactly what the Pool Service has put in the pool, but my guess would be something was introduced with a metal sequestrant that is HEDP or phosphanate based. I am not on a well but water utility company provider.




Thanks for the question

I'll first address the phosphate issue. Don't be concerned about the phosphates. I've had pools on my pool route that had over 1000 phosphates and the water was perfectly crystal clear.

Yes phosphates are food for algae, but the chlorine already kills the algae, and since phosphates are safe to swim in, there's no reason to worry.

Here's a good post about that. A little long but worth the time investment. Be sure to read the comments on the next page as well:

High Phosphates Over 1000 & Cloudy Water

If there's an algae problem and phosphates have been proven to be a small contributing factor, then you might be able to use a phosphate remover, otherwise you're wasting your money.

Nitrates are a source of food for algae, but you don't hear too much about that. It's because there's nothing, to the best of my knowledge, that can reduce the amount of nitrates in a pool.

Since you can't lower the nitrate amount there's nothing to sell so the chemical companies can't make money.

Next is the yellow algae issue. I'd like to have your complete chemical readings:

Chlorine, CYA (cyanuric acid/stabilizer), pH, Alkalinity, Calcium Hardness, and Metals (iron and copper). It makes troubleshooting much easier and the process of clearing up your pool will go much faster.

You should be able to get these fairly easily from your pool service. They should keep a record of all the weekly readings and have them readily available to you. If they don't produce them you need to find out why.

95% of the time these things happen it's because the pool water is not balanced correctly. When I get your readings I can look them over and give you an unbiased and professional opinion.

To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Swimming Pool Phosphates".

Check back to this post for updates or answers.

If you need immediate assistance (within 24 hrs) or for emergency personal assistance, you can make a donation of your choice and I'll answer your questions by phone.

Contact Me

Donation

Hope this helps and have a great Summer.

Robert

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Yellow Algae Stucked On The Pool Walls

by Liz
( Bakersfield, Ca)

I drained my pool due to severe algae problem (yellow and green). Now that the pool is empty, there's so much yellow algae stucked on the walls that can't be brush off. What do I need to do?




Thanks for the question Liz

First, the question doesn't say what kind of pool it is, whether a vinyl, fiberglass, or plaster/concrete pool. For the latter you can do either an acid or chlorine wash with a metal bristled brush. You may want to get a local and qualified pool guy to do that part. If you have a vinyl or fiberglass pool you'll want to use a normal vinyl pool brush.

For organic stains such as yellow and/or green algae you'll want to refill the pool and shock it. It's 1 gallon of liquid chlorine to increase the FC 10ppm per 10k gallons. You'll also want to use the correct brush for you kind of pool. You may need to shock 2 - 3 times and keep the FC level up to 12ppm while brushing 2 - 3 times per day. This will not only kill any possible residual algae but it'll loosen up algae adhering to the pool surface.

Keep filtering 24/7 and backwash once per day, or if you have a cartridge filter, spray it out once per day.

To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Yellow Algae" category.

Check back to this post for updates or answers.

If you feel your situation is more complex and want immediate assistance (within 24 hrs) you can make a donation of your choice and I'll answer your questions by phone.

Have I helped you find a solution to your pool problems? Did this information help you? Please consider making a donation to help keep this site going. Thank you.









Have a great Summer.

Robert

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Dreaded Mustard Algae Hard to Kill

by Sandy
(San Diego)

I have an above ground 14 foot metal frame pool (2750 gallons). I have been dealing with the dreaded mustard algae for the past week + and im not sure and i don't know what to use to raise the chlorine that high since i use a cartridge filter along with a floating chlorinator.

I have been using 1" tablets, but having trouble getting chlorine to the level you mention. I used hth algae guard at the dose recommended by hth and now have bubbles consistently in the pool. Ive been running the filter for about 16 hours now...so the question is, should i super shock it now or wait for bubbles to disappear?

If i should super shock, what would the correct amount be? By the way, it has been brutally hot for San Diego and i cant last that much longer before humping in with the mustard...it has gone down quite a bit since i started but i really think the piece missing is getting the chlorine to that high level.

Also my water bill will be sky high, please help either on the website or by email. Thank u very much!!

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swimming pool care, basic pool care, above ground pool maintenance, inground, salt water

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