Chem levels--post pool refill

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Dalancas

0
Bronze Supporter
Jan 30, 2014
26
Henderson, NV
Pool Size
11340
Surface
Plaster
Chlorine
Liquid Chlorine
SWG Type
Pentair Intellichlor IC-40
Looking for insight into whether these readings are in acceptable ranges or not. TFP tool suggests adding stablizer and some acid to bring FC down. After refilling pool 2 weeks ago (copper exchange in heater ate up by low PH), I am leary of making many changes. I am new to pool chems, but need to do better staying on top of it.

Pool is in part shade, in sunny Las Vegas. BTW, I have not put the heater back online, so water temp is around 45F now. Using 2 tabs trichlor, but used dichlor to bring FC up after fill. Also added 1.8oz soda ash at that time. No other treatments or chem adds have been done

Testing with Lamote ColorQ Pro-7

Chems-2-4-14.jpg
 
:wave: Welcome to TFP!!!

First, I will just say that we do not put much faith in the ColorQ or any digital testers as there is no way to know if it is properly calibrated or just spitting out garbage.
There is no way your CYA has swung from 3 up to 25 and back down to 16 ... that is just not possible. Your CH also could not have gone from 592 and down to 240 in one day and then back up to 318.

The continued use of tablets will drive the pH and TA down and the CYA up ... this is not a good long term solution especially since you likely do not close your pool. You will need to switch to liquid chlorine.

If you choose to believe these results ... There is nothing dire in your numbers, other than the FC being a little high for your low CYA level. But if you are going to use tablets for awhile, then the CYA will continue to rise.

If you want to learn about the chemistry, read Pool School starting with:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool

And feel free to ask questions as they come up.

BTW, were you using tablets before the heater went bad? How are you adding the tablets to the pool?
 
Like the others have said these numbers just don't make logical sense, CH and CYA can generally only be lowered through water replacement or reverse osmosis treatment (CYA will SLOWLY break down over time, but at a very low rate, below the typical testing errors, and on the scale of months or years, not days unless the pool has swamp like conditions). CH is always going to rise as it is left behind by evaporation and then raised by water addition until it gets so high that it forms scale. Trusting those numbers is like trusting the fuel gauge on a car that reads higher after you drive a hundred miles than when you started your trip.
 
Thank you for the responses, good to learn new things (even as an old guy). I will look for a new test kit, even though I just bought the one I have. Pool store recommended, but that doesn't always factor as the best recommendation.

Looks like I will change to liquid to clorinate going forward. Reading about it here, it seems a better alternative for my small pool than the trichlor tabs.

To answer your question on prior use of tabs, I used a floating basket and used about 1 tab per week, with the temp maintained at about 82F. We turned it up for use but maintained the 82F when not using the pool (1x /week in winter). I must admit, I made the mistake to allow the chems to get so out of whack that it dissolved some of the copper from the heater exchanger. Two mistakes, actually. I used a very old test kit, and hadn't done a test in over a month. I also didnt maintain the chem levels for several weeks while I was out of town for work. Heat exchanger developed a crack and would no longer fire, but the discoloration of the water already told me what I didnt want to admit. Adding a chelating liquid turned water a not very nice blue.

Sorry to ramble. But, figure if it helps others avoid my mistakes, then its worth the effort.
 
Welcome to the forum Dalancas!

We all make mistakes and have let things get out of whack at some point. Sounds like the pucks took your pH down pretty low, and most people aren't aware they can do that.

Important thing is taking a step in the right direction and it sounds like you are. Glad you found us, and hope you stick around.
 
linen said:
Welcome to tfp, Dalancas :wave:

What was your reason for draining and refilling?
Click to expand...

Linen, the TDS was pretty high late last season so I had planned to drain the pool anyhow. The copper levels were very high from the erosion of the heater core as well, so it made me do it only a little sooner than I had planned.

The cupro-nickel heat exchange shipped today, so I should get back to heated water sometime next week when it arrives.
 
Like Linen says TDS is a somewhat meaningless number, once upon a time before there was a separate test for CYA it may have been helpful, but these days it is nearly useless. TDS counts CYA, Salt, etc. all lumped into one number
 

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+1 to the above....

TDS is absolutely useless if you don't know what is creating that number. Everything dissolved in the water contributes to it. You can assume a lot from TDS, but it really doesn't tell the whole story at all.
 
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