Need help with Chlorine please (new pool)

[roll tide]

My VINYL LINER pool is about 2 months old now. The last few days I haven't been getting a chlorine reading with my kit. I took it to the store today and here are my results:

Temp: 80 F
Free Chlorine: 0.3 ppm
Total Chlorine: 0.3 ppm
Combined Chlorine: 0.0 ppm
pH: 8.1
Hardness: 0 ppm
Alkalinity (w/ stabilizer
correction) - - - - - > 131 ppm
Cyanuric Acid: 30 ppm

Pool size is 18 x 36 ft. 24000 gallons or so.

Polaris AutoClear system. Polaris says, according to system readings I gave them, the system is producing chlorine. My salt test strips say I have about 3500 ppm of salt so everything looks normal to me except for slightly high pH. I run my pump from 8 a.m. to 10 p.m. daily and the AutoClear for 8 hours. What about the CYA? It's on the low end. Do I need to raise it and how do you do that? I can see the bottom of the pool but the bottom is a little slippery and I'd like it to be a little clearer.

My pool builder says it's the hardness?? But he admits he's still learning these systems. Any advice??? Thanks.

[CarlD]

If your pool is vinyl, hardness doesn't matter. If it's concrete, plaster, etc, you'll need to raise it to between 200 and 400ppm. But don't waste your money if it's vinyl!

Your pH is high. Normal is 7.3-7.8. It may account for that slippery feeling. Use either muriatic acid (hardware stores) or dry acid (pool stores) to lower it. SWGs and plaster pools both trend toward high pH so you have to compensate.

Alkalinity looks a tad high for concrete/plaster, but get pH down and I'll bet it measures just fine.

I think your chlorine is 'WAY too low--no matter what .5 is the ABSOLUTE MINIMUM and even that is frequently too low.

Normal FC when CYA is 30 should be 3 to 6ppm, but those rules don't always apply with a SWGs. There, you have to rely on our SWG owning members.

[Poolsean]

SuperDude Carl,

I have to strongly disagree with you on calcium and vinyl liner pools. Calcium is one of the factors that affect the saturation index. IF the water is scale forming because calcium is not adjusted and is low, a higher pH and TA level will cause the water to be in a scale forming condition, which will affect the salt chorinator cell immensly! Scale on the cell is the worst condition for the life of the cell.
I would recommend that you suggest that they maintain balanced water according to the saturation index.
The opposite of the low calcium argument is that if the pH and TA are also low, the water will be very aggressive and will corrode metals.

[CarlD]

Oops!

Sean is absolutely right---calcium levels ARE important when you have an SWG even if it's a vinyl pool. I missed that (must have been sleep-posting )

However, I must disagree and say that ONLY when you have an SWG or a heater (gas or heatpump, not solar) is calcium important to a vinyl pool. Otherwise I stand on the 0 to 500ppm as acceptable calcium levels for vinyl.

The SI is really not otherwise a useful tool for pool maintenance. It's actually mis-leading and proper analysis of the basic tests will keep your water clear more effectively. My Cal level is about 70 now--or it was a month ago. I only test 2 or 3 times a summer and ONLY if I'm using Cal-Hypo for some reason.