UGH! My first positive CC test. What did I do wrong?

[broncosrul]

Newly built pool this July. I have been doing TFP since I took over from the "startup guy". He didn't do much. No CYA, no calcium, no measurable chlorine a couple days after he left. Since then, I have added things to get close to all the TFP recommended levels. CYA at 40, TA 80, CH 325, etc. I test the FC and pH almost every day and the other items about once a week. I normally test in the evening after work and I have never shown any CC. Our pool is in direct sunlight almost all day and I generally go through about 2ppm of FC per day. I tend to keep my FC on the higher side just to avoid the chance of it going below the minimum. Based on our usage, I feel like if I build to 5 then it wouldn't take much for me to end up below 3, so I tend to build to 7 and usually don't drop below 5. We have a lot of trees, but I generally fish out the leaves relatively quickly.

Anyway, I was taking my son camping this weekend, so I built up the FC to 9 since I wasn't going to be able to check it for about 2 days. When I came home today, I did a full test. Below are the results. I tested the chlorine twice because of the positive CC test. Tests from TF100 kit.

FC 4.5 (lower than I expected, but technically okay)
CC 0.75 (it had a very very slight pink after 1 drop and very clear after the second, so it is just a guess. Officially, I guess it is 1)
TA 80
CYA 40
CH 350
pH 7.6

Possible contributing factors (I don't exactly know what drives CC other than the chlorine is being used up).

• It has been really windy and there were more leaves and flowers in the pool than normal, several had sunk to the bottom
• Also, it is cooling off and more leaves are just falling period. The skimmer was really full today.
• There have been fires nearby and it is smoky (so bad they are cancelling activities)
• I found some fine black things floating in the spa and pool. Not sure if it is potentially ash or just new bits of tree ending up in the pool.
• I tested the water in the heat of the day rather than the evening when I normally do.

I fished out all the leaves and added enough liquid chlorine to get it back to 7 (according to Pool Math, but didn't check it made it there).

Would any of these things cause a CC reading? I never let the FC get below 3, so I don't know what happened. If I test again tomorrow and it is okay, so I be fine? Or do I need to go through the dreaded SLAM process?

 

[JamesW]

I wouldn't worry too much about it. It should go away on its own. Maybe run at 10 ppm for a few days to clear anything starting to grow.

Do an overnight chlorine loss test to see if there is anything that's in the water.

Check the cyanuric acid level to make sure that it's where you expect it to be.

 

[kimkats]

You are doing such a great job taking care of your new baby pool! I love that you were able to do everything you have just from reading here! That makes me so happy!

So..............you are fine. I really think you nailed why the slight cc happened-more stuff in the pool. What you can do to make double sure is the OCLT as seen here: Pool School - Perform the Overnight FC Loss Test (OCLT) The only reason you cannot use last night is that you did not check to see where the FC was after adding the chlorine.

Now if you want to push the FC up to SLAM level, or just under if you want to swim, you can. It will not hurt anything. It might not be needed but if it makes you feel better then..............do so. I am all about doing what makes me feel better so thought I would say this.

Kim

 

[broncosrul]

Thanks for your replies. It makes me feel better. I guess I didn't really connect that dead leaves are essentially the same as having algae in the water in terms of using up FC and creating CC. (I was thinking it needed to be living, but that doesn't make sense because I know that organic matter from swimmers isn't necessarily alive). Am I understanding it correctly?

Now I am going to be even more paranoid about keeping the leaves out. BTW, it appears that the CC is now under control.

Also, thanks for all the info on the website in general. When I was getting my pool built, I started by just asking my friends who had pools about how to take care of it. Not surprisingly, it was the typical pool store method, test strips, a gallon of chlorine once a week, acid as needed, and shock once a month. No mention of CYA. Now that I understand how things work, I can only imagine what their test results would look like day to day. I feel lucky that I found this site before I had any problems.

 

[JamesW]

Overall, you're doing an excellent job. You have a very good understanding of how to maintain the chemistry. Thanks for being here.