Cloudy, then green with a never ending chlorine demand

[Watermom]

Hmmmm......... now, that's different.

BTW -- Welcome back. Nice to have you back on the forum this year!

[cleancloths]

Today pool is fairly clear in shallow end but still has a green tint in dark end.

Total and Free Chlorine both read 2.0
pH is 7.0
Total Alk is 50.

I just added another 4 pounds borax, 12 pounds baking soda and 1.5 gallons chlorine.

[aylad]

If it's still greenish in the deep end, I'd go back to shock level and hold it there until it all turns blue..

Janet

[CarlD]

What is your CYA reading? With that, we can tell you what an effective chlorine level is.

[cleancloths]

What is your CYA reading? With that, we can tell you what an effective chlorine level is.

Need to go out and get that tested. I did not add any last year, and only used about 20 pucks all year. When this mess started I added 4 pounds, but that is all I have to go on right now. I just don't understand why the pH keeps dropping.

[cleancloths]

Just checked pool this morning after making yesterday's additions:

Cl Free 0.75
Cl total 1.5
pH 7.3
Total Alk 100

So, except for chlorine it is looking much better. Added another 3 gallons bleach.

I'm going to take a sample to the "pool store" and have them test it today to find out what the CYA level is.

[cleancloths]

So I went to the pool store and had them test the water. They have a fairly sophisticated setup. They have a bunch of square-sided "testtubes" that each have powdered reagents in them for a set test. They use a pipet to inject water into each one and then use a computer controlled colorimeter to directly measure and record the readings into the computer. Any way, here is what they came up with:

Chlorine Total and Free both 3.8
pH 7.7
Alk 90
CU & FE ~0
Stabilizer 10 ah ha!, BUT wait...

How can we believe the stabilizer is only 10? Wasn't it on Saturday that I added four pounds of CYA to my 20x40 IG pool. Doesn't that increase the level by about 30 all by itself? So, now what????

[Watermom]

What is your pool volume? How did you add your cya and if you added it to your skimmer to dissolve in the filter, have you backwashed any?

It may be that it just hasn't dissolved yet. It takes a long time. Or it may be that their result is inaccurate. CYA readings seem to be one that pool stores often get wrong.

Is the pool looking better? Keep at it. You're doing the right things.

[chem geek]

I don't care how sophisticated their equipment may seem, but most pool stores test inaccurately, especially for the CYA test. I don't know whether it's training, lack of calibration, use of old reagents, or what, but you should use you own good Taylor K-2006 test kit for doing water chemistry tests. Nevertheless, they could be right about this one if the CYA didn't fully dissolve.

It can take several days to a week for the CYA to show up in the tests, depending on how quickly the CYA dissolves. It is slow to dissolve -- the fastest method has pure CYA hang in a sock or stocking over a return flow. Next best is in a skimmer sock or equivalent in the skimmer (careful -- you have to have alternate flow to the pump so you don't crack your skimmer). If you just add the pure CYA directly to the skimmer to get caught in the filter, then you should not backwash for a week and it will be slower to dissolve since the rate of water flow is quite slow when dispersed in the filter.

There is a liquid CYA called Instant Pool Water Conditioner that dilutes into the water right away, but it's about twice as expensive as pure CYA, though it also has the benefit of being roughly pH neutral.