Pool not showing Free Chlorine but combined is high

[Owlman]

I am very new to the pool world, less than two weeks. So when I got the pool I had the water tested, since the CYA was 104 the pool service guy said that the best thing would be to drain 35% of the pool so I did and it brough the CYA to 73 when I brough the water to another pool store for testing. At that time the PH was 8.1 , the free chlorine was 0.05, total chlorine was 0.32 and combined was 0.27. The pool store said I needed to used seaboard instant shock and slow release tabs which I ignored as the tabs would have raised my CYA back to where it was. to reduce the PH I used dry acid and reduced it to around 7.8 (not quite sure as I have test strips). I then added three 121oz jugs of liquid clorox 8.25% to try to bring the pool FC up to 10 (based on the pool calulator) to shock it and from what I read reduce the combined chlorine. The next day I tested the pool and its showing still no free chlorine at all. I have ordered a taylor tk2006 test kit so I can actually get a clue as to my levels. I don't know what is going on and I need some help because right now I can't use the pool. If I use the CYA/chlorine chart in order to shock my size pool it says to use 5.5 jugs of 121oz 8.25% bleach to bring it to the shock level of 28, that seems like a ton of bleach and I just want some confirmation before I go ahead and dump that much bleach into the pool. In desperate need of help because its not holding chlorine. Thanks

Tom

 

[cowboycasey]

Tom, You have taken the first step...

unfortanatly the pool store tests just can not be trusted.... how does your pool look?

You have already seen why its so hard to SLAM your pool with a high CYA level, it just takes so much chlorine to get done... until you know exactly what your CYA is at you do not know how much chlorine to add..

if your pool is green or on its way, you may not have enough reagents in the k2006 kit but we will get to that later...

keep asking questions, reading as much as you can, and post test numbers once you receive your k2006

 

[Owlman]

The pool looks in great shape. There was green algae on the sides but I vaccumed it all off and the water looks clear, the pool looks inviting. I'm going to get the water tested at the pool stores computer to see what has changed

 

[cowboycasey]

make sure you get a read out of the pool store water test, just so you can see how far off they were when you can check it your self.. You will be supprised, I promise

 

[Owlman]

So I got the pool store water test, a first look at their computers and printer told me it was testing on some outdated equipment likely from the 1980's. When I got the print out the levels were off the chart and no where near what the previous pool store water test told me. I sure hope no one relies that place for advice. I'm going to wait until I get my test kit in before doing anything except educating myself on this website. never realized how shady this business can be.

 

[Scuba_Steve]

Dot Matrix Printers FTW!

You will be safe adding a gallon of bleach a day until your test kit arrives. It is always best to keep some FC in the pool. A half gallon to a gallon is about what your pool should be losing a day under normal circumstances.

 

[Owlman]

So I got my TF-100 test kit today and tried it out and went through the tests a few times. this is what I got
PH= 8.2
FC= 0
CC=0.5 but the test might be messed up because when I added the powder it stayed clear then I skipped the next step and added the reagent and one drop and it cleared instantly
TA=130
CYA=65

I added the PH down dry acid at the pool calculator recommended dose of 42 oz to get it down to 7.5. I believe the next step once the PH is in line is to SLAM the pool. Is that correct and how soon can I start to do that, do I have to wait a certain amount of time after I put in the dry acid before I can get a good PH reading?

 

[cowboycasey]

you need to wait at least 30 minutes to make sure everything is mixed well then test... most everyone here uses muriatic acid from lowes or hardware stores, its way cheaper and does not add anything else to your pool..

Once PH is between 7.1 to 7.3 you can begin to SLAM.. your PH may be over 8.2, that is the top of what can be tested, so test again to see where you are at..

 

[pooldv]

Retest PH after 30 minutes running the pump to validate PH and start SLAMing.

 

[Owlman]

PH is now at 7.4, should I lower it even more before slamming?

 

[Swampwoman]

7.2 is recommended for a slam because that helps increase the chlorine's effectiveness. Once you're slamming, ph tests will not be accurate, so it makes sense to drop it a bit lower now

 

[cowboycasey]

I agree. Try to get it to 7.2

 

[Owlman]

Will do, thanks!

 

[kimkats]

Look at you! Getting a good test kit AND following directions! THANKS!

Now take a before pic and post it using phototbucket so we can watch your pool clear right before our eyes! Take a pic a day. That will help you see the changes as they happen!

Kim