Chemical Analysis questions

[Mishellee]

My chlorine levels have been high for over a week, and I haven't added chlorine in over a week and a half, and ph is low. I use the Taylor K2006 test kit. I was getting,
free chlorine 5ppm
Combined= 5ppm
Ph= 6.8
Cya= well above 100. My pool is clear. So I took a sample to our local pool company, and had them test. I'm attaching their readings. I'm more confused now, then I was. Any help would be appreciated! Do I need to drain water, and refill? I have used tri-chlor granules for the last 4 years, with no problems. However, the last 2 openings my pool has remained pretty clean all winter, so I haven't had to vacuum on waste. I'm wondering, if that is why my cya is so high this year.
16'x32' inground, vinyl liner, sand filter
24, 000gal

 

[ajw22]

Your Trichlor has given you low pH and high CYA. Not the way we recommend managing pool water chemistry. I suggest you read ABCs of Pool Water Chemistry

You should do the No Drain Water Exchange

Retest your CYA doing the following...

CYA > 90 dilution Test
For CYA > 90ppm, repeat the test adjusting the procedure as follows:

1. Fill the mixing bottle to the lower mark with pool water.
2. Continue filling the mixing bottle to the upper mark with tap water.
3. Shake briefly to mix.
4. Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark.
5. Continue the test normally from step 3, but multiply the final result by two.

If you need to dilute the pool water further then apply these ratios:

Pool water	Tap or distilled water	Multiply result by
1	1	2
1	2	3
1	4	5

Note that when doing a diluted test not only do you multiply the range of the test you multiply the error rate of the test, so results are a ballpark - not an absolute.