Brand new water - where do I start?

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S

Sgowitt

0
Aug 13, 2018
17
Goodyear, AZ
I just drained and refilled my pool with fresh water. I want to make sure I do this right and hoping for some help. I tested the new water with my TF-100 kit. Current readings are as follows.

FC - 0
PH - 8.2
TA - 170
CH - 250
CYA - off the charts(I could see the black dot at bottom of tube even after it was full)

Pool store told me to add conditioner but wanted to make sure I do this in the right order.

Any help is appreciated.
 
As you drained and refilled with fresh water, there would be no CYA in the pool water. You must add it. As it appears you use liquid chlorine each day for your chlorination you should add 40 ppm worth of CYA granules using the sock method. Keep 3 ppm FC in the water. Add MA to lower your pH to 7.6. Be preprared for it to rise quickly as your TA is high.
 
All at the same time. Space out the MA and liquid chlorine by 15 minutes or so. Be sure to pour them slowly at a return with the pump running.

You will need to add liquid chlorine every day.
 
Your reading the cya test result to be backwards. When you can't see the dot that is your cya number, since you can see the dot at a full tube your cya level is less than 20 or 30 depending on the tube used. If you were able to completely drain your pool then it is truly 0, but if you did a mostly drain and refill then act like your cya is 20 until you can get a reading on the test.

Ignore pool store testing or advice, it's both wrong.
 
So i am having trouble getting my CYA up to 40 for some reason. I added 6 pounds via the sock method about two weeks ago, and it only got up to 20. I added another 2 pounds this week and now up to 25.

Do I keep adding until I get to 40? Doing something wrong? Here are my test results from this morning.

FC 0.5
PH 8.2
TA 130
CH 200
CYA 25

Thanks in advance!
 
NO more CYA. At 8 pounds you have added 60 ppm. Something is wrong with your testing method.
When you do the CYA test, try this next time.

Once you have your solution ready, back to the sun, etc. Fill the vial to a line, say 80, lower the vial to your waist level and glance for the dot, you see it, add solution to the 70 line, glance, see it, repeat until you no longer see it with a glance. Then use the CYA value one step above the line you read. So if you stopped at 50, use 60 ppm CYA.

The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....

The CYA would have also lowered your pH, but you are testing 8.2.

What brand CYA did you use?
 
CYA takes practice, and the main ingredient of a CYA test is the ambient light. It needs to be a sunny day. Turn your back to the sun and shade the tube with your body. If you dont, the direct light can potentially penetrate through the side and give you a false "low' reading.

With the tube shaded, only hold the tube with your thumb and forefinger. If you use too many fingers, then the right amount of light wont get through and you can get a false high..

Also, I would suggest with the same solution, repeat the tests several times and take the average as the correct level of CYA. If you do the test correctly, all the tests will be about the same. If your test method is inconsistent or faulty, then so will be the test results.
 
I would suggest maintaining your FC based on a 60 CYA using the FC/CYA Levels, for now. You do need liquid chlorine to be added daily.

How sure are you of the pool water volume? Do additions of chlorine or acid result in the expected change?

Let the water circulate for a week and see if the CYA gets to at least 50 or so. There is error in the testing process and a 50 ppm result would be within that error range. But since you started with new, fresh water, you know your starting point was 0. So what you have added is in the water.
 

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The description of that CYA product says it is a 'neutral buffered isocyanuric acid' product. That should be OK, but have to admit I have never seen that type of description before.
 
Interesting. Ok. Well it’s alresdy in the water so I will deal with it. Adding the chlorine and acid has produced the results I expected since refilling. Much better than before the drain. I am pretty sure of the pool volume. Measured a few times but I didn’t build this pool and the previous owners did not leave me paperwork. Pool builder is out of business now too.

Thanks for the help this morning! Really appreciate it. I’ll keep working on this.
 
I also like mknauss' advice to assume your CYA is 60 for now. Recheck your test methods and math before adding anymore CYA.

If you put 60 ppm in there, it's in there.....maybe just not 60.

We just have to figure out why the math is off........ Pool size? Testing method?, etc.
 
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