Introduction, Specifications and a Question

[DawizNJ]

If your fill water has a CH of 90, how did your pool's CH get so high?

That's a question I have as well. In the past, I've always relied upon the pool store to test our water. It's always been in the middle of the expected range when they tested it. Yesterday we ran a sample over to the store for a comparison, and they returned with 210 as the CH level. For all I know, it's been slowly climbing or high for years.

I re-ran the test this morning, on both the pool water and the water from the hose. My test consisted of applying drops of the reagent, swirling to mix, and looking down the comparator tube to the white (red/pink at this point) dot at the bottom of the tube. I applied drops of reagent until that dot turned blue. Maybe my testing process is flawed? I had been looking at the color through the side of the tube, and ensuring the entire thing was blue...which accounted for the higher reading. Which process is correct?

My results:
Pool water: 300
Hose water: 90

I do not fully understand what raises CH levels. I've read that applying chemicals that contain calcium can do it (makes sense). I've used many of Leslie's products over the past 4 years, for whatever they recommended. While that may not be the cause of the CH level, it may have contributed. Sadly, I don't have the ingredients handy.

Also, every year I have to fill in some water from the hose. Even with the application of an Aqua Door and plugging up the holes in the skimmer and return port I still lose water to below the skimmer. I'm hoping that as long as my CH doesn't rise, I can slowly bring it back down into a more acceptable range with those refills.

Thanks for all your help!

[aylad]

You pobably have just used cal-hypo powder to shock the pool with, if you've been operating based on the pool store's recommendations. Don't use any more cal-hypo, and the levels should drift down as you lose/refill water. 300 is a little on the high side, but as long as you keep your pH and TA fairly low, and don't add any more calcium, it shouldn't create a problem for you.

[DawizNJ]

You pobably have just used cal-hypo powder to shock the pool with, if you've been operating based on the pool store's recommendations. Don't use any more cal-hypo, and the levels should drift down as you lose/refill water. 300 is a little on the high side, but as long as you keep your pH and TA fairly low, and don't add any more calcium, it shouldn't create a problem for you.

Ugh, you're 100% correct. My powder of choice was the Powder Plus. I had a bag left over from last year sitting on my shelf. After reading the ingredients, it's 73% cal-hypo.

I'm using nothing but bleach now. Well, except for the tri-chlor tablet in the floater...which I only plan to use until my CYA reaches 50.

[Watermom]

Mystery solved!

[PoolDoc]

Hi Daw;

Two quick notes:

1. Let's be sure we're talking about the correct kit (K2006) and not the K2005. When you test chlorine, do you match colors, or do you add drops till the color disappears.

(Your pH test results sound like a possible high chlorine result -- but that's not consistent with your test results UNLESS you have a K2005! Also, pink isn't really a phenol red color, so if you would, read this post: http://www.poolforum.com/pf2/showthread.php?15322)

2. You have a sand filter. If you have left over cal hypo, there is a way to use it up, chlorinate your pool and NOT raise your calcium level further. But we need to resolve any questions about pH first.

[DawizNJ]

Hi, PoolDoc.

The kit reads K-2006 Complete (FAS-DPD chlorine) on the label. The chlorine tests are done using drops until the color disappears.

I ran through the post you linked and saw all the numbers in the tests. As of this morning, my pH test resulted in a orangish-red color. I just got done with a 15ppm shock (it's at 9.5 FC, 0.5 CC now), so I'm going to retest it this evening. Before the shock I was getting an orange color on the pH test.

[Watermom]

What was the pH reading?