added ph+ and alkalinity anhd now have turquoise/black spots

Problems relating to pH and total alkalinity.
Increase ph, increase TA. Reduce pH, reduce TA.
pH chemistry advice and techniques for the pool.

Re: added ph+ and alkalinity anhd now have turquoise/black s

Postby krista » Sun 03 Aug, 2008 19:58

How long will I need to wait to see any change in those black spots? It the pool swimmable?

Anonymous wrote:No need to wait.

krista wrote:ph is now 7.4 and TA is 160

I have metal out, should I wait till sundown to add it?


Re: added ph+ and alkalinity anhd now have turquoise/black s

Postby Guest » Sun 03 Aug, 2008 21:59

I missed this post for some reason. This explains some things.

I've never used a pool frog chlorinator but have read up on them. Sounds like a good system until you realize what it does to the pool over time. I think you are now seeing what it can do.

It has 2 components: the mineral pac (zinc, calcium, silver and COPPER). These are supposed to dissolve slowly into the pool. Silver and copper are known algaecides. Problems happen over time as the levels of these minerals go up or if they are dissolved quickly.

The other component is the tri chlor pac. This form of chlorine is very acidic and contains CYA. In the right doses this is fine. Over time the CYA builds up to levels making the pool very tough to manage. Being acidic it will drive the pH and TA down.

What I guess happened with you is the water got acidic (low pH) from the tabs and dissolved the mineral pac too quickly and you got your stains. The low pH may have also hit the heater's heat exchanger which is normally copper.

Probably more than you want to know and you just want it clear so you can swim. I wanted to give you my opinion and the reasons why.

I can't tell you if you can swim or not without seeing the pool.

To get rid of the green, vacuum to waste if possible. Vacuum slowly so you don't stir it up. If you can't vacuum to waste you'll have to clean the filter often to get it out before it causes problems there.

Take an old sock or nylon, crush up a few vitamin C tablets and put in sock. Figure a way to attach the sock to your pool pole and then hold it on top of the black stain for a few minutes. If the stain lifts it's a metal stain.

If you are able to do that I can tell you the type of treatment to do to get rid of the black. If it's black algae, that would be completely different.

My advice on the pool frog is stop using it. That is my own opinion and not everyone would agree but it is not something I would use in my own pool. I do use tri chlor tabs but I monitor the CYA and pH levels very closely.

Ok, fingers are tired, will respond to further questions etc.

Anonymous wrote:I am bringing a sample to the store shortly. Should I pick up something for black algae too, just in case that staining is black algae or just treat it as a metal stain for now? How do I get rid of all of the turquoise stuff.

My clorine is the pool frog clorinator.


added ph+ and alkalinity anhd now have turquoise/black spots

Postby krista » Mon 04 Aug, 2008 20:02

tried the vitamin c thing - and no progress. Just treating with one more sequestering agent. Pool is cloudy and black floor is not getting better.:(
pool user

added ph+ and alkalinity anhd now have turquoise/black spots

Postby pool user » Wed 14 Apr, 2010 17:48

see me all i do is when my pool gets green i shock then vacuume then baam :thumbup: like that me and my kids are in and swimming again :D

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