What algae?

[Saraphee]

This has started to invade my pool. At first I thought it was Black Algae and used a product called "Black Advance" the problem was not resolved. Your help in identifying and providing a cure will be much appreciated.

[JimHuaHin]

Depending on the size of the pool, may I suggest a strong dose of chlorine.

[AgMech Cowboy]

I don't own a pool and never have, but it looks like mold to me. Can mold grow underwater and in the presence of pool chemicals? I don't have an answer for that. Just a stupid comment, maybe. 

[mrfill]

This might help

 

https://www.swimmingpool.com/blog/black-algae-and-your-swimming-pool/

[3STTW]

The earlier link from @mrfill pretty much says it all about black algae - I get loads of it in my pool if I drop the pH ball.  Chlorine hits don't get rid of it because it raises the pH even more and black algae thrives.

 

The link above describes how you should scrub the algae before adding the Black Advance, it doesn't say that you should turn off the pump for three days afterwards - this is when the treatment really does its work. You also need to get the pH down well below 7.0 before you start. Try to avoid using hydrochloric acid because it eats the grout faster than the algae. Cyanauric acid powder or "pH minus" powder works well.

 

All the same, the picture tells me that you need to re-grout the pool ASAP. If it is black algae, it's gone too far and the roots have destroyed the grout - you can already see the tile edges which can be a disaster if you don't deal with it. Once the water gets behind the tiles it's pretty much game over and an very expensive repair job.

 

 

[Woof999]

As mentioned above, you absolutely have to scrub the algae to remove the top protective layer.

 

Thereafter even a scrub with a chlorine tablet will do a good job of removing much of it. Many of the black algae liquids are full of copper, which could also become a problem if the levels get too high.

[Nong Khai Man]

21 hours ago, JimHuaHin said:

Depending on the size of the pool, may I suggest a strong dose of chlorine.

Yep That should get Shut of it.....

[Nong Khai Man]

13 hours ago, 3STTW said:

The earlier link from @mrfill pretty much says it all about black algae - I get loads of it in my pool if I drop the pH ball.  Chlorine hits don't get rid of it because it raises the pH even more and black algae thrives.

 

The link above describes how you should scrub the algae before adding the Black Advance, it doesn't say that you should turn off the pump for three days afterwards - this is when the treatment really does its work. You also need to get the pH down well below 7.0 before you start. Try to avoid using hydrochloric acid because it eats the grout faster than the algae. Cyanauric acid powder or "pH minus" powder works well.

 

All the same, the picture tells me that you need to re-grout the pool ASAP. If it is black algae, it's gone too far and the roots have destroyed the grout - you can already see the tile edges which can be a disaster if you don't deal with it. Once the water gets behind the tiles it's pretty much game over and an very expensive repair job.

 

 

 it's pretty much game over and an very expensive repair job.UNLESS You hire the Mr Fixit HERE In Nong Khai, He can Stick tiles back on & Re-Grout while the water STAYS in the Pool Well That's what he Told Her Indoors & She Believed HIM ( To My Cost )......

[Tropposurfer]

As a pool owner of many pools I'd say thats an algae not a mould. As far as I am aware mould needs oxygen to grow and can't doesn't grow under water.

 

You have to scrub if all off, then refill pool and chlorine dosing to kill off the small algae particles of algae still in the grout and in the pool water.

Algae is very tough so after cleaning lots of it off you gotta attack the base where its is growing in the grout. Visual removal only isn't enough to kill it off entirely.

 

It looks bad enough to warrant emptying the pool to do that to me.

 

Then you readjust your pool chlorine to cleanse the water, and after running the filter system at max and cleaning the filters a few times, and or changing them out for new cartridges once this process has been done. 

DON'T get your head underwater while this is being done, as the algae might be dangerous to you if ingested or entering nose, eyes or ears.

I'd get a good pool guy to come and check your entire system. The only way I've ever seen such algae as this growing is because the maintenance was consistently poor e.g. filtration system not working properly over a period of time.

Often its all these issues in concert, creating a cascading effect along with failure to test and adjust Ph/chemical levels regularly especially after rain or after refilling pool during dry season evaporative periods.

Edited February 9, 2023 by Tropposurfer

[unheard]

20 hours ago, mrfill said:

This might help

 

https://www.swimmingpool.com/blog/black-algae-and-your-swimming-pool/

While that page does provide some useful advice, it doesn't sound too competent in the end by stating: "Continue to shock your pool once a week".

[unheard]

17 hours ago, 3STTW said:

Chlorine hits don't get rid of it because it raises the pH even more..

Not entirely correct:

 

Does Adding Chlorine Raise or Lower pH?

Depending on the type of chlorine you’re using, it will either raise or lower the pH in your pool.

Chlorine tablets are typically trichlor with a low pH level of around 3.

Being acidic, adding chlorine tablets to your water will lower the pH of your water, though this effect may be insignificant if your pH level tends to increase over time – which is common in swimming pools.

Powder or granular chlorine can be more varied. You can find it as trichlor, dichlor, or calcium hypochlorite.

While dichlor is slightly acidic, it’s reasonably close to neutral with a pH level of 6.5, which means it’s going to have a much lesser effect on your pH compared to trichlor.

Calcium hypochlorite, however, is highly alkaline with a pH of around 12, so this is going to raise the pH level of the water (as well as increase the calcium hardness level, for that matter).

Finally, liquid chlorine is sodium hypochlorite with a pH level of around 13, so it’s also going to increase the pH of your water. However, liquid chlorine only temporarily raises pH, effectively making it pH neutral in the long term.

https://poolonomics.com/how-does-ph-affect-chlorine/#does-adding-chlorine-raise-or-lower-ph

[unheard]

3 hours ago, Tropposurfer said:

The only way I've ever seen such algae as this growing is because the maintenance was consistently poor e.g. filtration system not working properly over a period of time.

Not because of filtration deficiencies.

He got algae due to improper water balance.

In most cases his algae problem can be quickly fixed by shocking and scrubbing, then filtering all dead algae out and then repeating until it's all completely gone.

But it will be back again unless he fixes his water imbalance, especially free chlorine levels.

That would require periodic testing of his water to make sure it's balanced, with appropriate for his pool, levels of free chlorine.

[indyo]

you should correct the ph at 7,2 then you should perform a pool chlorine shock and let your filter working for hours, if you have that issue one or both ph or chlorine level are wrong or your filter doesn't run enough hours per day,

 

[Saanim]

Your diminished tile grouting gives you "an advantage" in case of your neglected care for the algae growth. ???? The algae like to settle there instead of spoiling your water. In these days of very bright sunshine they have grown much more easily.  

 

Now, when you want to get rid of them fast, you can scratch them with a sharper brush, or line-by-line with something like a sharper chopstick or a longer wooden stick. Afterwards, vacuuming the mess laying at the floor.  

 

Then, it will still need something more to get rid of them completely. With a strong chlorine you will need to lower pH (i.e. a lot of pH Minus, or HCl acid). That's not only not cheap and slow but also not good for your diminished tile grouting, it will eat the grouting more.

 

If you use a copper sulphate, a handful properly dissolved and distributed directly in pool, it will go faster and more properly - and cheaper. The water will be first milky, it will need a good filtering, the best 25h/day. And of course, frequent backwashing of the filter. 

 

Once you have finished the algae removal you should take better care in order not to face it again. There are many ways how to do it, every pool owner will swear on his one only.  I do it with the (ir)regular handful of copper sulphate once in 2 - 3 months, then a spoon of common chlorine once in 1-2 weeks. And no need to bother with the pH measuring, the higher one is harmless for the grouting and for the humans either. Then, for the whole year I enjoy my crystal clear water.