Floundering in the dark here

[chicha]

Wal-Mart and other store brand bleaches are a chlorine/caustic plant by-product. Chlorox is the only brand I'm aware of that actually makes a household bleach on purpose. The off-brand bleach is made by adjusting the chlorine concentration of a chlorine/caustic solution that is produced when an imbalance occurs in the chlorine/caustic plant (usually because of selling more caustic than chlorine one week then more chlorine than caustic the next). No attempt is made to control the caustic content (within reason) and as a result the excess caustic can and does very widely from batch to batch. That's why you will sometimes need to add acid after using a store brand and sometimes not. I stopped using Wal-Mart brand because it was costing more to buy the hydrochloric acid than it would to buy the chlorox.

This brings up a point that concerns me since using non-Clorox household bleach in my pool. I'm in Latin America, so the choice is pretty much off-brand bleach. After adding a gallon one night recently, the following day some swimmers reported a burning sensation or stinging in the eyes. I won't receive my Taylor test kit for another week, so I'm not able to report on any test values at the time.

The word caustic has been mentioned. Something that is caustic can burn the skin. Could my non-U.S., off-brand of bleach be responsible for this burning sensation due to a high concentration of lye? Lye increases the pH. In general, does a high pH in swimming pool water cause stinging in the eyes?

I've just learned today that one of those swimmers that experienced this effect in my pool, also experienced the same effect today in a public pool, where they also reported a strong smell of chlorine. I've learned from reading this forum that that is not due to too much chlorine, but rather to too little free chlorine in the water.

I don't know if the following belongs in a separate post, but my original use of bleach a few weeks ago was related to the appearance of some green algae. I added a gallon and the green algae disappeared completely. What I have now is black spots on the pool walls and floor. I'm nearly certain this is algae, too. But when I added another gallon of bleach at night, and then checked the following day, the black spots were still there. This was five days ago. Yesterday, we added a gallon of muriatic acid thinking that maybe the pH was too high. No effect. [From reading this forum, shocking the pool with chlorine is how to deal with that problem, but I'll wait for your reply to this post. Again, still waiting on the test kit. Floundering in the dark here.]

 

[Isaac-1]

Re: Clorox Vs Cheap brand of bleach

The admins will probably split this off into its own message thread, until then do you have any type of test kit at all available to you? Doing one time doses of bleach is unlikely to solve your algae problem, you have to maintain high chlorine "shock" values until all the algae is dead, otherwise it will just start growing again and overpower your normal level of chlorine.

 

[chicha]

Re: Clorox Vs Cheap brand of bleach

The admins will probably split this off into its own message thread, until then do you have any type of test kit at all available to you? Doing one time doses of bleach is unlikely to solve your algae problem, you have to maintain high chlorine "shock" values until all the algae is dead, otherwise it will just start growing again and overpower your normal level of chlorine.

I should have it by Tuesday. I'm sort of baffled as to why one application of bleach rapidly eliminated the green algae, but not the black. Maybe because the black is more firmly adhered to the walls and the floor? The green could be moved by slightly pushing it with a brush; not so the black. The black required hard brushing. Are these different types of algae?

 

[duraleigh]

Are these different types of algae?

Yes. I once read there are more than 7000 species of algae. Balck algae is very difficult to get rid of in pools. YOu must keep your chlorine high and brush as often as possible with a stainless steel brush.

 

[Stuamurr]

Chlorine levels do not cause irritation, pH levels do, the eye socket and skin have a pH around 7.5 which is why we keep pH at that level so it's comfortable for bathers, the smell of chlorine at the public pool was through the production of chloramines (or combined chlorine) which is not getting broken down quick enough, lye does allow pH to rise, but not by much, once you have your test kit, you will know better and with a pool which is maintained to correct levels you will become troublefree.

 

[Isaac-1]

When dealing with black algae be aware it will also try to hide in hard to reach places where there is poor water circulation (under and inside pool steps, etc.) , if you don't get it all then it will just keep coming back.

 

[chicha]

Chlorine levels do not cause irritation, pH levels do, the eye socket and skin have a pH around 7.5 which is why we keep pH at that level so it's comfortable for bathers, the smell of chlorine at the public pool was through the production of chloramines (or combined chlorine) which is not getting broken down quick enough, lye does allow pH to rise, but not by much, once you have your test kit, you will know better and with a pool which is maintained to correct levels you will become troublefree.

Regarding burning/stinging sensation around the eyes, could combined chlorine cause this? I don't know what the pH of combined chlorine is, but is the issue high or low pH, or either?

 

[Stuamurr]

It's the two urban myths of swimming pools, smarting eyes are "usually" caused by ph out of range, whilst a smell of chlorine is "usually" caused by high cc's, which is usually in turn a result of low chlorine levels.

High cc's will cause bather discomfort and more nasty things like pathogens, but the main culprit is for the most part pH being incorrect.

 

[chicha]

It's the two urban myths of swimming pools, smarting eyes are "usually" caused by ph out of range, whilst a smell of chlorine is "usually" caused by high cc's, which is usually in turn a result of low chlorine levels.

High cc's will cause bather discomfort and more nasty things like pathogens, but the main culprit is for the most part pH being incorrect.

You're contradicting yourself, aren't you? In the earlier post, you stated "Chlorine levels do not cause irritation, pH levels do..." Then you say that it is a myth that smarting eyes are "usually" caused by pH out of range. Then, finally, you say the main culprit is for the most part pH being incorrect.

In what way am I misunderstanding what you wrote?

The possible culprits which may be at work causing this report of eye stinging/burning are:

1) Combined Chlorine being too high.
2) High pH in the swimming pool water
3) Lye contained in off-brand bleach
4) A gallon of bleach added to pool. Pump was not used to circulate bleach prior to pool use 24 hours later. (the reason for this is that the locking ring on my Pentair Clean and Clear pump is damaged and sometimes will blow off. I've ordered a new one. In the meantime, I let the poolperson maintain the pump, which is every Thursday.) Prior to adding that gallon of bleach, there was a light oil-like sheen on part of the surface as well as some soap-like bubbles.
5) algae?
6) CYA levels too high?

 

[chicha]

Are these different types of algae?

Yes. I once read there are more than 7000 species of algae. Balck algae is very difficult to get rid of in pools. YOu must keep your chlorine high and brush as often as possible with a stainless steel brush.

Would shocking the pool eliminate this black algae - without the need for brushing? I know that pools should be brushed regularly, but am curious to know if shocking will completely dissolve this algae adhering to the walls and floor.

 

[jblizzle]

No. The algae forms a biofilm that protects it from the chlorine ... black algae especially I think. So you have to brush that off so the chlorine can be affective.

Posted from my Droid with Tapatalk ... sorry if my response is short

 

[Smykowski]

I've found that stinging eyes are the result of one of two things:

1. pH is out of whack, either too high or too low.
2. Acutely high levels of CC. This happens in my pool with a high bather load when those bathers have put too much sunscreen on. It goes away in less than an afternoon if FC is maintained properly.

 

[Stuamurr]

It's the two urban myths of swimming pools, smarting eyes are "usually" caused by ph out of range, whilst a smell of chlorine is "usually" caused by high cc's, which is usually in turn a result of low chlorine levels.

High cc's will cause bather discomfort and more nasty things like pathogens, but the main culprit is for the most part pH being incorrect.

You're contradicting yourself, aren't you? In the earlier post, you stated "Chlorine levels do not cause irritation, pH levels do..." Then you say that it is a myth that smarting eyes are "usually" caused by pH out of range. Then, finally, you say the main culprit is for the most part pH being incorrect.

In what way am I misunderstanding what you wrote?

The possible culprits which may be at work causing this report of eye stinging/burning are:

1) Combined Chlorine being too high.
2) High pH in the swimming pool water
3) Lye contained in off-brand bleach
4) A gallon of bleach added to pool. Pump was not used to circulate bleach prior to pool use 24 hours later. (the reason for this is that the locking ring on my Pentair Clean and Clear pump is damaged and sometimes will blow off. I've ordered a new one. In the meantime, I let the poolperson maintain the pump, which is every Thursday.) Prior to adding that gallon of bleach, there was a light oil-like sheen on part of the surface as well as some soap-like bubbles.
5) algae?
6) CYA levels too high?

Sorry I haven't had a chance to reply earlier, because its the Just Getting
Started Section I keep answers fairly simple, inkeeping with the request of the forum with more detail if requested, sykorsky's post is spot on though and covers the answer in sufficient detail.

 

[anonapersona]

Adding the bleach to the pool where you had green and black algae would have used up the chlorine and produced some combined chloramines. These are driven off by additional chlorine or carried away by the wind eventually. If your chlorine was used up, then you had to wait for them to be carried away by the wind. In an indoor pool that will not happen of course. Then since the black algae has a hard cap over it, it was not disturbed by the chlorine, which was soon used up by the green algae anyhow. So, the algae alone can explain the burning eyes. [edit] That is, because of the combined chloramines produced from the bleach that was consumed while there was not enough bleach left to fully process the CCs. Also, the oil-like sheen and the soapy bubbles also would have consumed chlorine, and created more CCs.

I suspect you need to do a full shock on this pool and scrub the black algae with stainless steel brushes and perhaps a trichlor tablet if you can manage that. Wear gloves or attach the tablet to a stick in some manner. Black algae is hard work....

Of course, the pH of the water alone could have irritated eyes. Was the acid added before the swimmers complained?

I cannot help regarding the lye. We read here that the pH effect of bleach is neutralized as it is consumed. Not sure if that helps.

 

[JasonLion]

Lye has no effect on eyes once it is throughly dissolved into the pool.
Algae and high CYA levels doesn't bother eyes either, though both tend to drive down the active sanitizer level which can allow pathogens which (very) occasionally make your eyes itch.

Low PH tends to make eyes itch just about every time. Most people don't react to high PH levels until they are really really high, which hopefully never happens.