Not loosing chlorine overnight, but pool green

[Sherra]

I'm opening my pool for the season and for the past 2 days I have had no chlorine loss (maybe 1 ppm) overnight, but my pool is still quite green (can't see the bottom of the shallow end). I would think that I'd be loosing chlorine quite quickly - and I was for the first 2 or 3 days of the opening process.

FC 27
CC 27
PH 6.8
TA 60
CYA was 50 yesterday but there is still about a half pound of CYA in the sock (getting ready for salt system)
Temp - don't know, thermometer broke and don't want to put the new one in until the water's cleared up, but it's freakin' cold.

I backwash about once a day (or when PSI raises, whichever comes first).

What am I missing??

 

[JasonLion]

Does your PH read 6.8 while your FC level is that high? Do you have a PH reading from before you started shocking?

When the FC level is very high the PH will read higher than actual. If you are getting that PH reading while the FC level is very high then your PH is way way too low, which will not only make it difficult to kill the algae, but can also cause damage to the pool.

 

[schrody]

I hope that CC number is a typo! I'm still learning but a CH (calcium hardness) reading may be requested as well. I would wait to add more CYA after you fix the pool color!

 

[Sherra]

The PH level should be accurate, it was the same before I started shocking. And that should have been TC, not CC. And my pool is vinyl liner, so CH is basically irrelevant.

 

[JasonLion]

Alright. Either way, a PH of 6.8 is too low. You should raise the PH up to at least 7.5. And the next time your FC level is below 20, and again the next time your FC level is below 10, you should check that the PH is still somewhere in the mid 7s. It is probably worth allowing the FC level to fall below 20 today or tomorrow just to be sure. Low PH can cause the vinyl liner to fade and/or become brittle.

Vinyl liner pools don't care if the CH level is low, but it is still possible for the CH level to be too high and cause scaling. You should get a CH reading at some point to check for that.

As schrody said, it is easier to fight algae before raising the CYA level. If it is easy to take the sock out then you should do that.

Algae can sometimes stay green even when it is dead. If the algae is all dead and your filter is working it can still take several days to more than a week for the water to clear up. In this situation, you should see a visible improvement in the water each day.

Remember to brush the entire pool once a day while it is at shock level and to keep an eye on the filter pressure and backwash/clean the filter as needed.

 

[Casey]

 

[Heckpools]

just wondering... Do you see algae on the walls or floor? Or does the water just have a green haze? Do you have well water?

again, im just wondering.. not saying this will lead to your answer.

 

[frustratedpoolmom]

Is your SWG off? If it's on that would explain why you're not seeing the FC drop quickly....

When shocking, to see if FC is holding, it is best to turn of the SWG.

Have you used any algaecides?

Have you had the water tested for metals? You'll probably have to go to the pool store for that...

 

[Sherra]

No metals, no well water, SWG is not active yet (installed and the installer turned it on just long enough to make sure it was functional - not enough salt in the pool yet to turn it on "for real" - waiting to add more salt until water is cleared up). I can not really see the floor or walls, the water is a cloudy green, not a "swampy green" (although it was swampy when I first opened it), but I can tell that things get stirred up when I brush. I do brush it at least once a day (sometimes twice). I did let the chlorine levels drop to 10 over the weekend. PH level was still low (about 6.8), so I added Borax and now it's up to almost 8 (I didn't even add as much Borax as suggested by the calculator), so will re-test again and add some muriatic acid to bring it down a little. I have not used algaecides in this pool ever. The filter does seem to be working because the pressure does rise every few days (I was having to backwash twice a day when I first opened the pool).

 

[frustratedpoolmom]

Okay, sounds like just an algae problem....read about defeating algae in pool school - keeping the FC at shock level consistently will clear the pool faster. Shock, brush, filter 24/7, repeat.....

The PH will read falsly high when your FC is above 10, so keep that in mind. It's best to test the PH when the FC is below ten and then make any adjustments. You don't want to lower it with MA when the FC is above 10 because your test result is likely not accurate, ok?

 

[Sherra]

OK, will not mess with PH yet...will just keep attacking it with bleach, brushing, backwashing (the other 3 b's) - filter stays on until everything is clear and stable...(then will go on a timer 2x day).