Introduction, Specifications and a Question

[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?

[DawizNJ]

My water has gotten cloudy again.

Since the last algae cleanup I got the water sparkling clean and made sure I tested the water every morning and evening, focusing on the chlorine levels (using the K-2006 Taylor test kit). Since July 1st, the lowest reading I've gotten was 6.0 free chlorine. Since my CYA has been 30 up until last week, when I increased it to 50, I figured it should be more than enough chlorine according to the best guess chart.

We've had our trees cut down this past week with the last day of work being on the 18th. Some sawdust settled to the bottom of the pool, probably a six inch circle, which I vacuumed up. On the 18th, we had a heavy bather load followed by some rain on the 19th. After the rain, the water became cloudy...although mildly. On the evening of the 18th, my FC was 8.0. On the morning of the 19th, the FC was 7.5. I dumped a little chlorine in the pool when the rain started, since my last algae outbreak happened during some rain. In the evening of the 19th, the FC read 9.0. I did my best to make sure the FC didn't drop too low.

Today, the water is very cloudy - blue in color, with a hint of green. I'm on day 2 of treating it with bleach, trying to keep it at 20ppm. Brushing, Vacuuming, etc. go along with it.

My numbers, as of this morning:

FC 20.0
CC 0.0
CH 290
TA 100
CYA 50
pH 7.4 (before the chlorine shock)

I'm going to do an OCLT tomorrow morning to see if I'm still losing chlorine overnight. I'm confident I'll get the water clean again, but I'm concerned I'm either doing something wrong or missing some fundamental step or understanding.

I had thought that keeping the chlorine levels at 6.0 or higher would prevent the algae from returning, but that appears to be incorrect. I'm wondering what I'm missing? I'd like to prevent this from happening in the future.

I probably haven't provided enough information to determine the cause, so fire away if I have neglected to include some details.