Bottom of pool started to be brown

[Anders Eriksson]

Since some week my pool have started to create more and more brown areas at the bottom. Most of it can be brushed and sucked up, but not all. And after a cleaning it is back very fast.

 

Pool is 43 m3

It has a salt chlorinator Emaux 15

Salinity now is little high due to a faulty meter and to much salt added. Abut 6.

Ph is 7.6 and Cl 0.6

Temp around 29

I tried to add solutoin for alges, but no effect.

What is causing this and how to deal with it?

[Naam]

2 hours ago, Anders Eriksson said:

Cl 0.6

you have brown algae because your CL is much too low for a pool exposed to sun!

[Naam]

2 hours ago, Anders Eriksson said:

Cl 0.6

you have brown algae because your CL is much too low for a pool exposed to sun. to get rid of them shock your pool at least twice (7.0-8.0 ppm) and brush, brush, brush. algaecide won't help!

[grollies]

3 minutes ago, Naam said:

you have brown algae because your CL is much too low for a pool exposed to sun. to get rid of them shock your pool at least twice (7.0-8.0 ppm) and brush, brush, brush. algaecide won't help!

Yep.

 

And a reminder for calculating required quantity of sodium hypochlorite liquid.

 

For a 43m3 pool:

 

43,000 / 1,000,000 = 0.043 litres per ppm

 

8 ppm = 0.043 x 8 = 0.344 litres of sodium hypochlorite.....

 

BUT

 

sodium hypochlorite typically supplied at 20% solution so you'll need

 

0.344 x 5 = 1.72 litres

[grollies]

33 minutes ago, Naam said:

you have brown algae because your CL is much too low for a pool exposed to sun!

Tried liking your post but for some reason TV just keeps coming up error.

 

So....

 

[Anders Eriksson]

Thank you Naam and grollies!

I have Soda ashes and something for schocking, is the name chlorine schock?

Which can i use?

[sappersrest]

A useful tool

https://www.totalpool.co.uk/index.php/resources/dosing-calculator

 

https://swimmingpoolchemicals.co.uk/dosecalc.php

 

This looks like a useful design tool I have not played around with it yet, used to do all my calculations the hard way, will play about with it in the week . and post later

https://draftsman.files.wordpress.com/2013/11/main-pool-lanai-new.xls

[sappersrest]

Not enough chlorine Soda ash raises your pH and chlorine shock will extra chlorine , I would also suggest at some stage to lowering the pH to 7.2 

 

I would suggest your chlorinator is not wok or the plates are clogged up

 

A useful tool

https://www.totalpool.co.uk/index.php/resources/dosing-calculator

 

https://swimmingpoolchemicals.co.uk/dosecalc.php

 

This looks like a useful design tool I have not played around with it yet, used to do all my calculations the hard way, will play about with it in the week . and post later

https://draftsman.files.wordpress.com/2013/11/main-pool-lanai-new.xls

[Naam]

2 hours ago, Anders Eriksson said:

Thank you Naam and grollies!

I have Soda ashes and something for schocking, is the name chlorine schock?

Which can i use?

simply chlorine in whatever form you have but preferably liquid chlorine should be used. at the same time you apply acid to balance the pH that will shoot up with the shocking. no soda ash! that would cause an additional pH increase.

 

as member "sappersrest" mentioned... your pH is too high. get it down to 7.0-7.2 (personally i prefer 6.8).

[Naam]

3 hours ago, grollies said:

Tried liking your post but for some reason TV just keeps coming up error.

 

So....

 

thaivisa bloken, rike no work!

[Anders Eriksson]

1 hour ago, sappersrest said:

Not enough chlorine Soda ash raises your pH and chlorine shock will extra chlorine , I would also suggest at some stage to lowering the pH to 7.2 

 

I would suggest your chlorinator is not wok or the plates are clogged up

 

A useful tool

https://www.totalpool.co.uk/index.php/resources/dosing-calculator

 

https://swimmingpoolchemicals.co.uk/dosecalc.php

 

This looks like a useful design tool I have not played around with it yet, used to do all my calculations the hard way, will play about with it in the week . and post later

https://draftsman.files.wordpress.com/2013/11/main-pool-lanai-new.xls

I suspect the cell is not working! I have only had it for 8 months and I have cleaned it two times. Latest 1 week ago. But i can allreado see it has started to build up scale. Normally I only run system 2+2 h per day, but very little use of pool. I run it at 100% at 100. Now I have started it to run continously. It will be very expensive if I should change the cell every 8 months! The cost of the cell is half of the total price. Here in Th it cost about 360 USD. I have tried to find a cheaper source.

So I will put Acid in to get the Ph at 6.8-7.2

How much shock chlorine should I ad? It is in powder form. What is the chemical name for it?

[grollies]

2 hours ago, Naam said:

simply chlorine in whatever form you have but preferably liquid chlorine should be used. at the same time you apply acid to balance the pH that will shoot up with the shocking. no soda ash! that would cause an additional pH increase.

 

as member "sappersrest" mentioned... your pH is too high. get it down to 7.0-7.2 (personally i prefer 6.8).

I disagree with your pH levels. Looks like an in-ground concrete pool. I keep my pH at 7.8

 

Recommended levels are between 7.4 and 7.8

 

I'd recommend Anders shocks the pool and let the pH level rise.

 

Also, get rid of the plant life round the pool.

 

There should be guidelines for how much Cl granule to add for the volume of pool water?

[Naam]

31 minutes ago, grollies said:

I disagree with your pH levels. Looks like an in-ground concrete pool. I keep my pH at 7.8

 

Recommended levels are between 7.4 and 7.8

any recommendation can be found by asking a bunch of eggsburts. my eggsburt is my wife who dictates since we have pools (~35 years) a pH of 6.8, preferably 6.2 - 6.4 which i find agreeable with my skin although i don't do like her 200 lengths every day.

 

by the way, most recommendations are 7.2 based on the average pH of tears to avoid eye irritation. moreover, the pH of human skin is quite low (around 5.5), i.e. anything value above that and applied for an hour or two reduces the skin's natural power to kill bacteria.

[Naam]

46 minutes ago, grollies said:

There should be guidelines for how much Cl granule to add for the volume of pool water?

get liquid chlorine from a pool shop. dissolving granules takes too long.

[Anders Eriksson]

One new thing I now noticed is this:

When I fill the glass with water to check Cl and add 4 drops from the yellow bottle and shake it. The tube is not showing any bit yellow which means 0 Cl. When I then let it stand and look after say 20 minutes the colour is very yellow, showing over 3.

Why is it like that?

Earlier I have noticed the change of colour when I shake the tube and no big change after that.

[Naam]

5 minutes ago, Anders Eriksson said:

When I then let it stand and look after say 20 minutes the colour is very yellow, showing over 3.

Why is it like that?

that's normal. but for a correct check it should be five drops.

[Anders Eriksson]

8 hours ago, Naam said:

that's normal. but for a correct check it should be five drops.

Even if the instruction says 4?

[Naam]

1 hour ago, Anders Eriksson said:

Even if the instruction says 4?

never heard of any set with 4 drops. but if you say so i stand corrected.

[grollies]

13 hours ago, Naam said:

any recommendation can be found by asking a bunch of eggsburts. my eggsburt is my wife who dictates since we have pools (~35 years) a pH of 6.8, preferably 6.2 - 6.4 which i find agreeable with my skin although i don't do like her 200 lengths every day.

 

by the way, most recommendations are 7.2 based on the average pH of tears to avoid eye irritation. moreover, the pH of human skin is quite low (around 5.5), i.e. anything value above that and applied for an hour or two reduces the skin's natural power to kill bacteria.

I misread the OP post as a pH of 7.2 instead of 7.6 so agree with SR that whilst shocking the pool Anders should at the same time reduce the pH to around 7.2 to improve the effectiveness of the shock treatment.

 

Also agree that Anders should buy sodium hypochlorite (liquid chlorine) instead of granules. When buying it, check the date of manufacture as it does not have a good shelf life (around 6 months). If it is not convenient to buy then use the granules.

 

I conceed that my pool water pH is high and I need to reduce it to around 7.4 to 7.6 to improve the effectiveness of the Cl, pool water at pH 6.2 is too acidic and surely going to have a detrimental effect on your pool shell and fittings?

 

Also pool water that acidic will start to remove natural oils from the body's skin.

 

Whilst I am no 'expert' (owned my first pool for 8 months now ) I tend to research a little bit and rely on the experience of others and 'professionals in the field' for advice.

 

Each to their own.

 

The consensus seems to be to maintain pH between 7.2 - 7.8

 

As in life, everything is a balance and if it works for you, great.

 

BTW, my test kit instructions specify 4 drops too.

 

IMHO

[Anders Eriksson]

I had one pond/pool man here, he said I should have 5 in Cl. What kind of tool is it to measure that?

[sappersrest]

Make sure that when researching make sure the info you read is reasonably up to date, a great deal of stuff on the net regarding pools is getting fairly dated  most of it comes from the 80s

 

Guidelines for chemical levels really do change  the 7.4... 7.8  is based on old research mainly done in the 70s . Later reasearch dictates that we lower the pH to make the hypochlorus acid far more effective.7.2--7.4 is now the norm.

if you read pages 13 ,14,15 of the publication listed below will give some better understanding. The recommendations are the latest offering from PWTAG . This a UK based organization who's recommendations on design are recognized throughout the world, perhaps withe the exception of the USA,

lovibond_handbook_gb.pdf

The WHO a good organization seem to sit on the fence as they always do recommend pH to be kept between 7.2--- 7.8.

http://www.who.int/water_sanitation_health/bathing/srwe2full.pdf

Page 95 5;10;3

 

[grollies]

30 minutes ago, sappersrest said:

Make sure that when researching make sure the info you read is reasonably up to date, a great deal of stuff on the net regarding pools is getting fairly dated  most of it comes from the 80s

 

Guidelines for chemical levels really do change  the 7.4... 7.8  is based on old research mainly done in the 70s . Later reasearch dictates that we lower the pH to make the hypochlorus acid far more effective.7.2--7.4 is now the norm.

if you read pages 13 ,14,15 of the publication listed below will give some better understanding. The recommendations are the latest offering from PWTAG . This a UK based organization who's recommendations on design are recognized throughout the world, perhaps withe the exception of the USA,

lovibond_handbook_gb.pdf

The WHO a good organization seem to sit on the fence as they always do recommend pH to be kept between 7.2--- 7.8.

http://www.who.int/water_sanitation_health/bathing/srwe2full.pdf

Page 95 5;10;3

 

I agree that 7.8 is a little high. I let my pool water settle for the first 8 months and have only added salt and a weekly dose of hypo just to help the salt chlorinator.

 

Last week was the first time I ever added acid and I'm adding it slowly until the pH is around 7.4 like you say to increase the effectiveness of the hypo and see if I can run the salt chlorinator on a lighter load.

 

Our bather load is very light, just me and the wife. The pool is 95% shaded. Cl levels are around 1.5

 

I firmly believe less is more with chemicals in pool water. I've no algae and the water is clear.

 

There's no way I'd run the pool water at 6.2 but that's just me.

 

Cheers, I've got the Lovibond handbook. Your input and advice is always appreciated here.

[Anders Eriksson]

50 minutes ago, sappersrest said:

Make sure that when researching make sure the info you read is reasonably up to date, a great deal of stuff on the net regarding pools is getting fairly dated  most of it comes from the 80s

 

Guidelines for chemical levels really do change  the 7.4... 7.8  is based on old research mainly done in the 70s . Later reasearch dictates that we lower the pH to make the hypochlorus acid far more effective.7.2--7.4 is now the norm.

if you read pages 13 ,14,15 of the publication listed below will give some better understanding. The recommendations are the latest offering from PWTAG . This a UK based organization who's recommendations on design are recognized throughout the world, perhaps withe the exception of the USA,

lovibond_handbook_gb.pdf

The WHO a good organization seem to sit on the fence as they always do recommend pH to be kept between 7.2--- 7.8.

http://www.who.int/water_sanitation_health/bathing/srwe2full.pdf

Page 95 5;10;3

 

I am grateful for getting these documents. Especially the first one will be good for me to learn more about pools!

[Naam]

1 hour ago, sappersrest said:

This a UK based organization who's recommendations on design are recognized throughout the world, perhaps withe the exception of the USA,

i wouldn't trust any publication presented by an entity from a country where tropical sun and tropical bacteria do not exist

[Naam]

46 minutes ago, grollies said:

There's no way I'd run the pool water at 6.2 but that's just me.

because you don't have like me a sister-in-law who is dermatologist.

[Naam]

2 hours ago, Anders Eriksson said:

I had one pond/pool man here, he said I should have 5 in Cl.

that's not surprising because TIT - This Is Thailand

[Jai Dee]

Most test kits you get in Thailand look like this... 5 drops required for each sample.

 

[grollies]

....and so another potentially useful thread descends, as usual, from informed debate, into disagreement and I-told-you-so's.....

 

sigh

 

for the OP:

 

Anders, do as SR, JD & Naam advise:

 

1) Get yourself the basic test kit for pH and chlorine as per JD picture.

 

2) Get yourself some hydrochloric acid & sodium hypochlorite solution

 

3) Give the pool a good clean

 

4) Shock the pool to around 10ppm chlorine using around 2 litres of sodium hypochlorite (20% strength)

 

5) Run the pool pump and filter for around 8 hours, cell switched off

 

6) Add hydrochloric acid to lower your pH - do this over a couple of days, adding diluted acid (and always add the acid to a bucket of water don't add water to acid)

 

7) Re-clean the pool brushing well and vacuuming.

 

8) Backwash your filter

 

Here's where I'd let the Cl levels decline naturally running the pool pump and filter as normal, keeping the cell switched off.

 

9) Once Cl down, run the salt chlorinator and sample the return water for Cl.

 

10) Check Cl and pH weekly.

 

Cl level should be between 0.6 - 1.5ppm

 

Ignore your Thai pool chap.

 

Hope this helps, anyone wanting to add/edit the above, feel free.

[Naam]

53 minutes ago, grollies said:

Run the pool pump and filter for around 8 hours, cell switched off

for brown and yellow (mustard) algae run 24 hours.

[Anders Eriksson]

1 hour ago, Naam said:

for brown and yellow (mustard) algae run 24 hours.

 

2 hours ago, Naam said:

that's not surprising because TIT - This Is Thailand

Pleas, explain.