FC above recommended range with copper piping

[MarkGLN]

FC - 7
CYA - 60
pH - 7.4

I'm keeping the FC level at 7-9 for my pool, which has plaster surfacing and aging copper piping. The 60 CYA, along with a pH of 7.2-7.8 will keep the copper piping from eroding, according to the wisdom of this board.

However, I have a little black algae I need to get rid of, and I'm a little concerned about raising the FC to near SLAM levels. My tentative understanding is that high FCs and a moderate pH, especially for a short period, will not cause damage to newer copper pipes. The question is will older copper pipes be safe as well?

The pipes in question have undergone stress in the last few years due to a PG who kept the pH too low, sometimes below 7. I'm not sure of the condition of the pipes except that they are not leaking. My goal is to prevent the development of leaks. At the same time, I need to get rid of the black algae which requires super high FC levels.

Can anyone help?

 

[mknauss]

Have you read the Pool School article on Black Algae? Here it is Pool School - Black Algae

You do not need to go to shock level FC if it is Black Algae. Read the article and see if that helps.

From the piping issue, I am not a metallurgy expert so not sure.

Take care.

 

[MarkGLN]

Have you read the Pool School article on Black Algae? Here it is Pool School - Black Algae

You do not need to go to shock level FC if it is Black Algae. Read the article and see if that helps.

From the piping issue, I am not a metallurgy expert so not sure.

Take care.

Yes, thanks, I read the article.

By SLAM FC, I was really talking about anything between FC 9 and SLAM.

Due to the uncertainty, I usually aim for FC 7 as the day-to-day level, not quite trusting 9 without more information. Anything above 9 is even more uncertain without more information.

 

[MarkGLN]

Anyone? (Never mind. This was answered in another thread.)

 

[Pool Amateur]

I believe ph is the major factor in eroding copper, however SLAM level FC will not hurt anything. This chart, Chlorine/CYA Chart by Chem Geek, is a chart that shows the different levels of oxidation power and their relationship to CYA. It includes Mustard Algae shock levels which should not be held for more than one day. I was afraid of the high levels of chlorine used til the science was presented.