Phosphates? High CYA!

[CarlD]

"Phosphate removal" became very popular with pool stores and services for a while until international relations cause the supply of a key ingredient, a lanthanum compound, I believe, to become unavailable. But it was always nonsense for 99.9% of the people sold it, if not 99.99%! Many people here have phosphate levels that would have pool stores winning Oscars with their dramatic eye-rolling, yet have perfectly clear, safe pools.

It's all about the chlorine!

I hate to say it, but you've obviously not been following the suggested courses of pool maintenance we recommend. Kelemvor has given you good advice that will save you money and I'll add this:
1) test your pool water AT LEAST 2x a day, 3x a day if you can manage and ALWAYS raise your FC back to 25ppm if it's below that.
2) Vacuum your pool to waste every single day until it's clear.
3) Brush your pool every single day to knock algae loose from the walls and floor. Not sure why, but when loose it's more vulnerable to the chlorine.
4) P.O.P.P. needs to be maintained 24/7. That's Pool Owner Patience and Persistence!

[chem geek]

Assuming the pool service was not using Trichlor pucks, they could visit once a week and add chlorine by having the CYA be high so the chlorine lasts longer and start the week with around 14 ppm or so and may end up at 4 ppm or so a week later. However, in your case, it sounds like it got out of hand and the chlorine wasn't lasting well enough so algae was able to grow when the FC got too low.

[onemsmom]

After the pool company owner came out and saw that the CYA really WAS that high, he agreed to a partial drain & refill. After talking to him, it seems an employee probably shot the CYA really high & skipped a few visits. He had similar issues with other clients and employee has been fired. With all of that said, my pool is still green ( I was away for 2 weeks), the CYA is still too high (90ish) and the chlorine is at 1ppm. Ugh. So he is obviously not dealing with the problem properly and I will take my pool care back into my own hands. I STINK at being consistent, so this is hard for me, but I will do my best.

I have forgotten how much bleach raises 1 ppm for my pool - could you please refresh my memory? I think it was 1/2 bottle = 1 ppm, but I'm not completely sure. I'm a 24' round - above ground - 13,000 gallons (I think).

Here we go again.

Thank you,

Jennifer

[kelemvor]

In 13k gallons of water, 1 gallon of 6% bleach will give you 4.75ppm. So if your bottle = 1 gallon, 1/2 of that bottle gives you about 2.4ppm. At 90cya you need to be over 20ppm to shock.

This is based on the best guess chart and your 90ppm cya. You need to KEEP it above 20ppm and keep testing for combined chlorine until your CC is 0, and you don't lose more than 1ppm FC between sundown one night and sunup the next morning.

Once that happens you can let it drift down to 5-10ppm for regular operations. I keep my pool at that level of CYA (because my swcg recommends that level) so you can definitely run your pool at 90ppm cya.

If you're not diligent enough to maintain things on a regular basis - and don't have a metal pool - then you might want to consider a salt water chlorine generator. You still have to stay on top of your pH (I usually dose with acid about once a week). A swcg won't help you clean up the mess though; you're going to have to do that the regular way.

[onemsmom]

Thank you so much!

[onemsmom]

Question - would adding extra bleach buy me more time between checking/adding or make this process go more quickly or would it just waste bleach? Ex. if I'm supposed to keep the level above 20, would it speed things up to keep it above 30, etc.?

Thanks,

Jennifer

[chem geek]

For shocking, a higher FC level makes things go somewhat faster but the chlorine losses from sunlight are greater since they are based on the percentage of FC. However, speeding up the algae kill isn't the slowest part of the process. The slowest part is then removing the dead algae via filtration.

As for regular maintenance, starting with a higher FC level will have it last longer, but because it drops as a percentage of FC you will be using more bleach. It's not "wasteful" so much as a trade-off between convenience of not adding chlorine as often vs. the extra cost associated with the larger amount of bleach that is needed.