Organic Matter & CC?

[rodrigo]

After a couple of busy weeks implementing BBB, the water is lookin' GREAT!

I REALLY like using my TF100, and finally feel like I know what's going on in my water... except for one thing. I always have a CC level of .5. I recently spent nearly a week at shock level. I did an overnight test, and my results were within spec... I lost about 1 ppm FC, and had .5 ppm CC. All is well? Maybe?

As I let the FC level fall, I began working on the Acid/Aeration method to lower my TA. From Saturday to Monday, I lowered TA from 180 to 80. pH is still slightly low at 7.2, but I've had it covered for a couple of days due to cloudy/rainy weather. This is when the water started looking REAL GOOD!

All this time, I'm still getting CC of .5. I add the 5 drops of CC reagent, and the sample turns the slightest shade of pink -- and it clears completely & immediately with one drop of the R0087 stuff. With ALL the shocking I've done, and as clear as the water is, I have a hard time believing there are still living algae in there. This led me to wondering: Can things OTHER than algae cause a detectable CC level? Specifically, what about tree leaves? My pool is quite close to two large hard maple trees. I'm very diligent about cleaining up the floaters & emptying the skimmer, but I almost always have a handful of leaves on the bottom. Can the breakdown of tree leaves in the water cause a measurable CC level?

Can I hope to ever have a CC that really and truly is zero?

Again, I sincerely thank all of you for your expertise and willingness to help!

 

[JasonLion]

Having just a little CC is normal. Some pools can never get CC all the way to zero. If it is really bothering you, raising FC levels slightly and letting the pool get as much sunlight as possible can sometimes help it go away.

CC is any combination of several different related chemicals. A few of them can last for some time before they finally break down. So it might be from tree debris, or it might be something persistent left over from shocking.

 

[chem geek]

Also keep in mind that you are using a 10 ml sample size in the FAS-DPD test so the one drop to have it turn clear means <= 0.5 ppm -- it doesn't mean actually having 0.5 ppm CC. If you use a 25 ml sample size, you may find that it still only takes one drop to clear so that really the CC is <= 0.2 ppm. This is typically the case in my own pool. Such a low CC level truly means nothing as there is always something in a pool that will register at least a small amount of CC, if the pool is open and/or used at all. It is absolutely nothing to worry about at such low levels.

 

[jefeyessica]

Does all of this mean that I could have a CC of 0, and still have living organisms in my pool? I have had a very high FC loss (4ppm a day), but have never tested overnight, because my CC is always below 0.5.

 

[dmanb2b]

the only way to tell is to perform the overnight test...if you lose more than 1ppm overnight, you may need to shock, but given your low CC level, you may just choose to raise your FC a little higher for a few days and see if that helps...4ppm sound a little high, but is not abnormal if you a in full sun all day