Balancing my water

[COpool5]

My 14k gallon plaster pool was new a year ago. This spring the pool builder came out to do an acid wash on some areas that had been stained or where the plaster was off. We filled the pool, the builder “balanced the water” (added acid and walked away) and now I’m trying to balance water and having a tough time.

Yesterday I added liquid chlorine (one gallon) and muriatic acid. This am when testing the PH was higher than I could read and the chlorine was also darker than I could read (they were approx the same color). I added muriatic acid first to bring the ph down (to 7.8 when I tested two hours later). However when testing chlorine at the same time I now register zero FC.

Help please!

 

[thetekgeek]

What test kit are you using to test your water?

 

[TinFoilHat]

How are you testing? You should be using one of the test kits we recommend so that your readings are accurate. You can't depend on accuracy from a pool store or test strips and you need a kit with the FAS/DPD chlorine test in it. A simple plastic comparator with drops for FC and PH isn't enough.
Test Kits Compared

 

[PoolStored]

Can you provide a full set of results from your test kit?
In general, it sounds like you added chlorine in the evening, tested in the morning and had a high FC. Makes sense, no UV at night.
You also likely did not add CYA yet to the water. Without CYA, 10 FC with sun will be .1 FC in 3 hours. Your FC was consumed during sunlight.
You took care of the pH, so you are good there.

Post your results, then raise your CYA to 30ppm, that will start to protect your FC.

Just Filled Your Pool with Water? Here's What To Do Next - Further Reading

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