High FC for over a week and some CC

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18x36pool

0
Jun 16, 2018
10
Bristol/CT
Hello all,
A little more background first. This is our first full year in owning a pool and when winter cover got removed it was a mess (green, very cloudy, leaves , twigs and other things). We raked all dirt debris as much possible, shocked the pool, ran our sand filter non stop for 3 weeks and also brushed/vacuumed walls and floor every day for the last week. It’s finally clear and blue after hundreds of$$ spent at pool store as recommended by them. Wish I came across this forum sooner and could have avoided lots of mistakes due to inexperienced staff at PS blindly following software recommendations and mediocre water testing. Although the last place I went to had digital tester and claimed it takes human error out but came home to only find it doesn’t match my k2006 results, go figure.
so anyway all that in the past and this where I’m based on home k2006 test results.
FC-10.8
CC- 0.8
ph-7.3
TA-145
CYA- 52
CH- 360 (again due to PS instruction to add 45lb of powder to increase hardness, now it’s too much)

i have turned down the chlorinator with tabs since cya is bound to get crazy high in a month at this rate. I read somewhere it adds around 1ppm a day. Also I have moved away from powder to 12.5% liquid chlorine since my CH is on the high side. Now to the real question,
how much longer should I wait for cc to reduce since fc is easily 10x. The appearance of pool is too tempting for the kids and we went in already once but I would really like the cc numbers to look better and bring fc to normal maintenance level. Why’s is it taking no so long to reduce. Last shock was a full week ago with 10gallons if sodium hypochlorite (I know it’s probably high but we were desperate since green wasn’t going away). Today I also added 3lb of mps/oxysheen to see if that can do the trick without more chlorine. Any help or insight is much appreciated.
thanks
 
Hi,

Before the real experts chime in and tell you, you should add your pool build stats to your signature -- e.g., size, equipment, plaster vs. vinyl, etc. (There's guidance somewhere on the forum and it helps people help you.)

Getting your own test kit and switching to liquid chlorine are fantastic steps you have taken! I followed pool store testing and recommendations (and chems) for years and got myself into big trouble before I found the forum. I'm not sure how often you are testing or if you did an overnight FC loss test (OCLT). That will tell you if you still have 'stuff' in the pool the FC is fighting -- whether visible or not. Pool School - Perform the Overnight FC Loss Test (OCLT)


Assuming all is ok, my FC loss is generally about 2ppm/day -- more when it's super sunny/hot/humid/lots of use. You should test your pool every day until you 'learn' how your particular pool/situation uses up chemicals -- then you can go to every other day or a bit more. Personally, I do it every day so things never get out of control.

Not sure if you found the chem calculator, but it will be your best friend. Here is a link: PoolMath

Depending on the state of your pool when you added 10 gallons of chlorine, 10 gallons on a 20K gallon pool will raise FC to over 60! If only a portion of that was needed to clear things up, you still had a long way down. The daily drop will be much faster when it's that high. So........that's a really long way of saying that a FC level of 10 after a week ain't so bad, IMHO. Also bear in mind that based on your CYA level, your FC should be somewhere around 8 always per the Chlorine/CYA chart: Pool School - Chlorine / CYA Chart


Hope all that helps. Good luck!
Jen
 
Thank you Jen for the links and insight. I will add stats to my signature soon after I figure out how to. If one thing I haven’t done so far is the OCLT. Yes it appears I do need to maintain FC at 8 given my cya level. Should I turn off CL feeder totally and move to bleach for maintenance at least this year? Does CYA reduce over winter? It would be nice to get some use out of the brand new Hayward offline feeder at some point. You are right it’s a lot of chlorine for 28000gallin pool to wear down. Looking forward to what the experts have to add.
-MR
 
Welcome to the forum! :handshake:

You have already received some great advice.

Yes, you need to transition to only using liquid chlorine at this time. Treat your CYA as 60 as you cannot read a 52 as the vial is logarithmic.

Your CYA reduces due to splashout and backwashing. Also if the pool overflows (inground pool?) due to rain. You will be lowering your pool water level for winterizing so that will reduce your CYA some too.

Do the OCLT as your CC is high and that typically indicates organics being consumed in your pool water.
Also use the 10 ml sample for FC testing. Each drop will equate to 0.5 ppm FC.

Watch your use of FAS-DPD reagents. You have the small K2006. You will need refills very soon.

You can swim in the pool as long as your FC is above minimum and at or below your SLAM level based on your CYA as shown [FC/CYA][/FC/CYA]. You also need to be able to see the bottom of the deep end.

Take care.
 
Thanks for confirming my assumptions. Yes, I went through most of reagent in couple tests due to 25ml sample test and high chlorine levels and will be shifting to 10ml moving forward but the only downside is accuracy in 0.5 increments.
next step is oclt but unfortunately it has to wait since the oxysheen oxidizer package I used to reduce chloramines says it will throw false chlorine levels up to 72hrs. Will keep you posted.
 
Got it. How long are we talking, days or weeks. How do I manage my cl levels during this “significant”period. Can I keep adding a gallon of grocery store bleach every 2 days just to be safe no matter test readings.
I can’t stop blaming myself for not getting to this forum sooner.
 
Best way is to check your readings based on what you add. If you add X amount of LC that should raise your FC Y amount, and after 30 minutes you test FC and get a much different number than Y, then the MPS is messing with your data.

It should not be weeks, but could be days.
 
So after running tests everyday for the last 3 days, it appears my pool consumes no less than 3ppm of cl /day on average. I’ve been adding a full jug of Clorox 8.3% to maintain fc in the 6-7 range. The combined chlorine level came down from last time but not 0. Since I’m using 10ml sample I don’t know if it’s 0.5 or 0.2 but with 1 drop the water turns clear. Isn’t this too much free cl reduction/day for cya 50-60?
 

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