oxidizer shock

[fhorta]

I noticed that even keeping chlorine level @ 6-7 ppms my water eventually begins to turn green. I been maintiaing water clear with algaecide called skill-it. I use 7 oz per week. I also got some oxidising shock to give it a boost and my question is that since the oxidizing shck is chlorine free, how would one measure if you reached shocking level as you would normally determine with a kit for chlori ne?

[BigDave]

I wouldn't use non-chlorine shock, there's no need. Do you know the CYA level? I also wouldn't use that algaecide. Chlorine will do the job if there's enough in relation to the CYA.

[CarlD]

BD and I are thinking the same thing. Have you always been using Tri-chlor tabs or Di-chlor granules to chlorinate your pool? If you have, you almost CERTAINLY have a very high CYA and a chlorine level of 6-7 isn't going to keep it algae-free.

We don't recommend using non-chlorine sanitizers when the answer for you is very simple:
1) You need to determine your CYA(stabilizer) level. That means you need a good test kit. Our first choice is the Taylor K-2006/K-2006C ( see http://www.poolforum.com/pf2/showthread.php/14994 )
2) You need to raise your chlorine level (FC--Free Chlorine) to the recommended shock level for your CYA level (which I suspect is over 100ppm). (Use the Best Guess table to determine that:
http://poolsolutions.com/gd/best-gue...ine-chart.html )
3) You need to run your filter/pump 24/7 till you can maintain the shock level for 24 hours, and you need to brush and vacuum your pool to waste every day.

[fhorta]

Cya is between 70 and 80. Cya has been as low as 50 and after shocking pool water would eventually turn green. I have done the "maintain shock level for 24 hours" methid then maintianing free chlrine 6-7 but eventually starts turning green. The algacide has been the only thing that keeps water clear. When I throw in oxidiser it boosts it. So was just wondering about how to measure the chlorine level or the shocking level, if possible. I have the taylor k 2006 . I run filter 6-8 hours. Its a sand filter. Ph, alkalinity, calcium all are in range according to kit test results. Thanks

[BigDave]

... the "maintain shock level for 24 hours" ...

Not how we recommend shocking here.
Keep FC at or above shock level until one full day after these three criteria: 1)The pool loses less than 1 ppm between sunset and sunrise 2) The pool has 0.5ppm CC or less 3)The water is clear. With CYA 70-80 your FC to chock is 20ppm.

... Ph, alkalinity, calcium all are in range according to kit test results...

We can help you better if you give us the numbers.

[CarlD]

fhorta: You can't really mix and match our advice with others advice if they aren't the same. If you have the K-2006, you simply run the FAS-DPD test using the R-0870 powder and R-0871 drops. You can measure up to 100ppm with it.

If you aren't keeping your FC at shock level (20ppm) as BigDave advises, YOU WILL NOT KILL THE ALGAE!