I'm a little confused... my pool (in ground, 33,000 gal.) is just slightly cloudy, and no signs of algae. The chlorine had run out while out of town for a day, so I figured that's why it was cloudy. I shocked with chlorine and over the next few days it cleared up to a point. Deep end still a bit cloudy. After I shocked and the chlorine started drifting down, my numbers were FC 5.6, CC .6, PH 7.4. Seemed like all was good. The next day, FC 4, CC 2.8, PH 7.2. That was confusing... why the raised CC? Then hubby said he opened the chlorinator and maybe the stabilizer from the pucks was too high. Checked that. CYA is low! Black dot never disappears when tester is filled to brim. I read that maybe a non chlorine shock may bring CC down, so tried that yesterday. CC came down to 1.6 last night. This morning, however, it's back up to 2. PH is now lower at 7.0, so I added PH plus an hour or so ago. I don't want to get in to this unending balancing game, though. Any suggestions? And any idea why the CC would be high? Btw, I test using the Taylor K2006C. Thanks!
CYA low, CC at 2.
- Thread starter ConnieStrnat
- Start date
High cc means that something in the water is being broken down by the chlorine. Although if you used non-chlorine shock, that can also give false CC readings.
Can you post a full set of test results? If there is ever cloudy water or algae or high CC's, the answer is always following the SLAM Process
Can you post a full set of test results? If there is ever cloudy water or algae or high CC's, the answer is always following the SLAM Process
The last results from a couple hours ago were: FC 2, CC 2, PH 7.0, CYA too low to register with vial.[/QUOTE]
With those results I say your next step is the OCLT tonight
www.troublefreepool.com
Perform the Overnight FC Loss Test (OCLT)
The Overnight Chlorine Loss Test tells if the SLAM is finished or if you need to start a SLAM. This article says how to do the OCLT.
www.troublefreepool.com
Was there anything besides chlorine added? There are all kinds of pool chemicals that contain MPS (Potassium Monopersulfate) and it will falsely read as CC.
I did hit it with some algaecide, and then later some non chlorine shock... Don't know if either of those contain MPS
LOL, ok, Clouseau! I checked and the non chlorine shock does have MPS. So, now what do I do? How can I be sure that's the problem? I started a SLAM, should I continue it? (Started SLAM Friday night... didn't see your response until just now) Latest results an hour ago.. FC 7.2, CC 1.0 According to the chart, since my CYA is so low, I only need to get to 12 with Chlorine. It dropped to 7.2 overnight, so I need to add more, but I'm out. Just on my way to get some, but should I? Nothing seems to have changed since I started the SLAM. CC holding at 1, and pool still a bit cloudy in deep end...Aha! We have a clue!Non-chlorine shock was probably MPS
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Cloudy in the deep end means SLAM until it's clear. You might just have to fudge a little on the CC test.
Do you think bringing up to 12 is high enough? And if I go higher will that help, hurt, be a waste of money?
Just follow the chart FC/CYA Levels
Those numbers were developed to be a practical compromise between killing speed and solar losses. Going higher won't gain you as much as you'll lose. You will gain more by brushing and vacuuming to get as much of the floating debris that is causing the cloudiness into the filter so it can get strained out.
Ok, Thanks, Richard..
I'm getting frustrated! For the last 3 days, the CC has been bouncing back and forth between .6 and .4 Last night I did the overnight test and this morning CC was .6 after spending all day yesterday at .4! FC is still falling more than 1 at night, though. This is confusing! How important is the falling FC compared to the CC?
I'm getting frustrated! For the last 3 days, the CC has been bouncing back and forth between .6 and .4 Last night I did the overnight test and this morning CC was .6 after spending all day yesterday at .4! FC is still falling more than 1 at night, though. This is confusing! How important is the falling FC compared to the CC?
Both the dropping FC overnight and the high CC levels are indicating that something in the water is being broken down. So I would not say that either or is more important. Also, is there a reason you are not using 10 mL of water so that each drop is 0.5 PPM? Or maybe that has not been suggested to you yet oh, I seem to make that recommendation to a lot of people everyday 
We've already ascertained that the CC is not really CC, but MPS. I don't think you can realistically use that as a factor to end the SLAM. If it degrades into something else and no longer reads as CC, great. But you could finish and still show CC because it isn't really CC.
The concern is the FC overnight loss. Remember, only two things consume FC: UV light and organics. There's no UV light from the sun at night so it has to be organics.
The thing is, CC levels are .6 or .4, so not high, but I agree the FC dropping at night indicates something in the water, so I'll keep at it. Btw, Why is using 10 mil water sample better? Seems like using a larger sample would be more precise, but then, I'm no chemist, lolBoth the dropping FC overnight and the high CC levels are indicating that something in the water is being broken down. So I would not say that either or is more important. Also, is there a reason you are not using 10 mL of water so that each drop is 0.5 PPM? Or maybe that has not been suggested to you yet oh, I seem to make that recommendation to a lot of people everyday
- May 3, 2014
- 58,767
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
A 25 ml sample is more precise. Just more precise than needed for pool water chemistry. Save the reagents. Using a 25 ml sample uses them up quite quickly.
Last night I scrubbed, vacuumed, and backwashed the pool. Added another dose of chlorine to bring it up to 10 (amount according to chart), closed the cover. This morning pool is clear, no floating debris, nothing settled on bottom, CC .4, FC 7.2. ARGGGHHHHH! There doesn't appear to be ANYTHING in the pool. I've been slamming for almost a week. Why is the FC dropping?! And does that mean it's not safe to swim in? Obviously why is it dropping is a rhetorical question, but what the heck? I feel like I'm just dumping gallons of chlorine in and nothing is happening. The numbers basically haven't changed since I started!
- May 3, 2014
- 58,767
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
You started about 4 or 5 days ago. Not very long into the process.
You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.
You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.