Taking forever to lower CC - over 15 days of SLAM!

[joshmoch]

Hey all, I have been shocking at 25ppm for 15 days. The pool was fairly green as we were renovating the house and were unable to attend to it. It has been crystal clear for the last 10 days and has passed the overnight chlorine test for the past 7 days. We have been maintaining shock for days now and can't get the CC down. We vaccum every day and brush every day. I have rinsed the filter 4 times throughout the process.

My question is, with all the pollen in the air here in Florida, could that be making my CC what it is?? Should I keep Slamming? I'm starting to get on the first name basis with the pinch-a-penny guys I've bought so much chlorine.....

CYA - 50
FC - 25
CC - 1.5
pH - 7.4 (at start of SLAM)
TA - 110
CH - 260
What Temp - 68 F

 

[mknauss]

Last year we had folks with issues of high CC's that did not make sense.

They cleaned their vials they did the FC/CC testing in with rubbing alcohol.

Magic -- the CC disappeared. You might try cleaning the vial.

 

[tim5055]

First, you are just a little high on teh FC, 20 is the level you want for a SLAM with 50 CYA.

Can I guess this is an outdoor pool with a screen enclosure?

 

[YippeeSkippy]

make sure if you do this cleaning trick you rinse the vials with fresh water before running a test.

 

[joshmoch]

As a chemist I should have thought about the condition of my reaction vessels....sheesh....feeling sheepish. I'll try that and see what I find. Hopefully that's the issue.

 

[joshmoch]

First, you are just a little high on teh FC, 20 is the level you want for a SLAM with 50 CYA.

Can I guess this is an outdoor pool with a screen enclosure?

We had tested the CYA at 60 at the start of the SLAM, but our latest test was closer to 50. I just kept it up at the 60 CYA shock for good measure. And Yes, outdoor with a screen

 

[YippeeSkippy]

Have you put anything in to the pool other than liquid chlorine? Any non-chlorine shock type products?

Maddie

 

[YippeeSkippy]

Aha! That screen is blocking your UV rays.

 

[joshmoch]

Have you put anything in to the pool other than liquid chlorine? Any non-chlorine shock type products?

Maddie

Nothing other than liquid chlorine.

 

[setsailsoon]

Josh,

How are you testing? Please put your pool info at the bottom in your signature. This will help our experts get their best advice to you the soonest.

Chris

 

[joshmoch]

I am using the Taylor FAS-DPD chlorine kit K-2006

 

[setsailsoon]

My question is, with all the pollen in the air here in Florida, could that be making my CC what it is?? Should I keep Slamming? I'm starting to get on the first name basis with the pinch-a-penny guys I've bought so much chlorine.....

Pollen usually floats on the surface. Is it possible you actually see yellow-greenish mustard algae somewhere other than the surface? This could explain the cc.

Chris

 

[joshmoch]

Pollen usually floats on the surface. Is it possible you actually see yellow-greenish mustard algae somewhere other than the surface? This could explain the cc.

Chris

I'm not actually seeing the the color of the pollen, but rather the little black pollen granular pieces from the oak trees that fall through the screen sitting on the bottom of the pool.

 

[setsailsoon]

I'm not actually seeing the the color of the pollen, but rather the little black pollen granular pieces from the oak trees that fall through the screen sitting on the bottom of the pool.

That could be adding organics that are reacting and consuming FC.

 

[tim5055]

A screen will block UV rays of the sun. CC is burned off by UV.

Were it me I woul dlet teh FC drift down, but keep it on the higher end of recommended and continue to watch the FC/CC. My gut is that teh screen is blocking a lot of your UV, but you may have dirty vials also....

 

[Aqua Lab Rat]

Organic (carbon-containing) chloramines can be much harder to get rid of than inorganic ones. Depending on the type of material the chlorine is combined with, it may not respond as readily to high levels of chlorine. Dr. Tom Tufano of Dupont has studied this and replicated it in the lab. Here is one article that talks about his work. As others have said, UV would help break them down.