Misinformation from pool store website???

[pypeke]

I saw this information on a pool store website..." The available chlorine in a standard 3" tab (Tri-Chlor) is 90%, which dissipates at a much slower rate. Liquid chlorine is great for quickly bringing the chlorine level up, but you will need to maintain the chlorine level at a much higher rate." So, if the tab is 90% chlorine and dissolves slowly, why do the companies add other stuff in the 10%? I guess it is impossible to make the tabs 100% chlorine because it is a gas? I never took chemistry so I have no clue.

Then, it said you would always have to add a pH decreaser after adding liquid chlorine. Is this true? My pH is always too high.

If the tab is 90% chlorine, then the other 10% is a mixture of calcium and stabilizer? (This is why CYA gets too high.)

When I used to use the 3" tablets, my chlorine test always showed medium light yellow. Now I use FC tests for chlorine. So, why is it that with the old test, chlorine should be in the middle color of yellow, but using the FC test, it will be a much darker yellow....basically, off the chart yellow compared to the old test method?

thanks,

 

[zea3]

You won't find calcium and stabilizer in the same tablet, they are a volatile mixture when combined. Many things will cause pH to spike, but liquid chlorine is not one of them. You can get a false high pH reading with high amounts of FC, but it doesn't matter what the source of FC is, dry or liquid.

 

[Donldson]

Ah pool stores and their, ahem, knowledge...

3 inch tablets are made of trichlor, that is what the percentage listed is measuring. Trichlor is a chemical compound of chlorine and CYA. When used it introduces both in to the water, at a 5-to-3 ratio. For every 10 ppm FC introduced by trichlor it also adds 6 ppm CYA. This is a chemical constant for trichlor. It does not matter what else is in the tablet, sometimes borates or metal algaecides are added, but for every bit of chlorine added CYA is also added in the 5-to-3 ratio.

And add acid to the pool when your testing tells you the pH needs decreased, not blindly just because you added other chemicals. Discontinuing to use a pool store website for advice will help immensely as well.

 

[pypeke]

I don't use their advice, but I was looking for 12.5% liquid chlorine to buy and I read the misinformation.

I have never read on TFP about liquid chlorine causing high pH so I figured the pool store was wrong again. I HATE using MA, but I hate dissolving pH decreaser even more.

I only test pH When the FC is normal.

So why is it okay for the old OTA test to be light yellow when chlorine levels are good, but when I use the FC test, it shows off the chart dark yellow? Should the color be the same?

I am keeping my FC on 6 or 7 every night according to the CYA chlorine chart. Is the old OTA test (light yellow) more likely to be the "minimum" FC number, which, I think, is 3?

We don't swim in the pool every day, but I put liquid chlorine (10%) in every night.

thanks