Total Hardness/No Mor Problems Questions

[pmastro1973]

I managed to lower the calcium level and acid level both by half. So now my calcium reading is 200ppm and the cyanuric acid is at 50ppm. I am using the chart from Pool Solutions that indicates the minimum chlorine level based on the temp/stabilizer level. With two gallons bleach in 30,000 gallon pool, I can get the free chlorine reading at 4.5ppm. I still have the black algae spots and not sure what I should use to try and get rid of them since I am not using cal hypochlorite shock anymore? I suppose just super chlorinate with the bleach to around 10ppm? Same thing as shocking with the granules, right?

[CarlD]

OK, let me untangle this a little:
First "acid level" refers to your pH level, not your Cyanuric Acid level, which is your CYA or Stabilizer level.

Second, Not sure HOW you lowered both your calcium and CYA levels unless you drained off half your water and refilled. I believe there ARE ways to lower CH, but they are complicated and require careful timing. Perhaps you are measuring them wrong.

Third, if you have black algae and CYA=50ppm, you need to shock your pool to at least 15ppm, not 10ppm, and keep it there till the algae is dead, usually several days. You'll need to brush the pool every day to knock the black algae loose so the chlorine can thoroughly infiltrate and kill it (Black Algae is tough stuff), while maintaining chlorine levels at 15 or higher. You'll need to run your filter 24/7 till you do. So, no, raising chlorine to 10 is NOT going to work. But using bleach to get it to 15 or higher WILL work, with patience.

Fourth: While chlorine is chlorine, you do NOT want to shock with anything but bleach or Liquid Chlorine and DEFINITELY NOT with granules. There are two types: Di-chlor, which adds almost as much CYA as it does chlorine, and Cal-hypo, which adds calcium. Since you just worked to reduce BOTH your CYA and CH levels, the LAST thing you want to do is re-introduce either. So stick to bleach/LC.