How long does it take to clear?

[bluskyguy]

Opened my pool about 10 days ago. CYA is 70. Ph was about 6.8 (added 200lbs of salt to get it up to 3400 ppm)
Alkalinity is 90. FC was pretty much 0. Immediately dumped required amt of 6% bleach to bring to shock level
of 20 ppm (pool calculator numbers). I know Ph is low,but figured salt would increase some. Now that I shocked
I wont get a good Ph reading. I brush at least 2 times a day. I add a couple gallons of bleach at night to keep
at shock level. Pool went from ugly green to GRADUAL clearing. The past 5 days have seen no progress.Shallow
end mostly clear,deep end hanging on to cloudy light green.

It seemed when I used Trichlor(shock) in the past as opposed to bleach, my pool would be crystal clear in 2 days
max. Does bleach normally take this long to clear? Also been running filter 24/7 for past 10 days, SWG at 100%
for past 3 days. Okay Im done.

 

[RobbieH]

according to the chart, your shock level is 28.
pool-school/chlorine_cya_chart_shock

From experience, you'll have to go even higher than that if you have mustard algae.

To answer your question, it took over a week to get my pool even starting to clear this last time, but I think my filter problem was keeping it from clearing the dead algae efficiently. And that was using trichlor to shock ... it takes too many bottles of bleach to get to shock level in a pool the size of mine.

 

[crookm11]

Are you using bleach to keep your FC at shock level or are you using the SWG? If you are using the SWG then you are probably not killing the algea fast enough and it continuse to grow. SWG are used to maintain normal FC levels after a pool is properly set up. Have you been cleaning filter often? You need to keep the FC at shock level continuously until you pass the overnight FC loss test. What kind of test kit are you using to check the FC?

 

[bluskyguy]

I use the bleach for shocking,SWG for supplemental. Im using TFT 100 test kit for readings.
According to my calcs using pool calculator shock level with a 70 CYA would be 20 while
mustard algae would be 27.

 

[crookm11]

Based off of this chart and this chart the normal shock FC level for 70 ppm CYA is 28. Mustard shock level is much higher. I don't think you have enough FC in the pool to fight the algea effectively. Try raising the FC and see what happens.

 

[JasonLion]

Your PH might be too low, which could prevent the chlorine from being effective. The common PH test will read PH levels below 6.8 as 6.8, so your actual PH might be much lower. Adding salt doesn't have any effect on PH.

 

[Shift_Nashville]

I thought I read that having a low PH will help the bleach be more effective? Or is 6.8 too low?
What should the correct range be when shocking the s**t outta your pool?

 

[frustratedpoolmom]

You need to do a couple of things. Turn off the SWG. Let the FC drop down to normal range long enough to get a ph reading. Shouldn't take very long to do this, if the water is still a light tinged green. In the meantime, Calculate your PH change using 7.5 as your goal for the pool calculator. Add enough Borax to reach this goal and let it circulate for a few hours while the FC is dropping. Once the FC is down to around 10-12 or so go ahead and check the PH and bring it in to range. 7.2-7.4 is good enough to resume shocking. Add more Borax if you need to. Then continue with liquid chlorine, hourly if you can, and save some your cell life. Are you confirming with an FAS-DPD test that you are reaching shock level?

Then do an overnight FC loss test, with the SWG off, when the pool is looking less murky. Its not necessary to wait until the pool is clear to do the overnight test, you can see if the algae is dead this way and if this is a filtration issue.