updated pool chemistry

May 22, 2008
16
Ridgewood NJ
#1
30,000 gallon IGP c DE filter
FAC 1.0
TAC 5.0
PH 7.2
TA 100
CH 300
CYA 30
The pool has gone from a swamp to almost clear, perhaps a slight green hue to water. I have added about 20 containers of bleach (182). From my readings on the site it seems I have to keep adding more bleach. Is this right? I have had to backwash the DE filter about 1o0times in the first 5 days but the pressure appears to be fine now. Should I add more CYA?
Thanks
Len
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,448
SW Indiana
#2
Yes, you need more bleach. Your free chlorine reading of 1 and total chlorine reading of 5 indicates 4ppm of combined chlorine. You need to raise the chlorine to shock level and hold it there until the chlorine holds overnight.

If the pool gets very much direct sunlight, you might want to raise your CYA by 10ppm to reduce UV burnoff of chlorine, but that can wait until you have clear water.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#6
As JohnT suggested, raising the FC level to shock level (around 13 to 15) with bleach and holding it there with testing and additional bleach till CC goes to zero will get rid of the CC.
 
May 22, 2008
16
Ridgewood NJ
#7
So I added 13 gallons of clorox to my almost clear pool about an hour ago. Using a DPD tablet test, the chlorine level initially read about 2 and then after 15 min becomes greater than five. I have ordered a FAS test and will have the water checked at Leslies tomorrow. I feel as if I am pouring dollars into the pool :). It did not take that much bleach to get the pool from swamp to clear. Why is taking so much more bleach now? How can an essentially clear pool consume so much chlorine? If CC is chlorine combined with algae in the pool, what is its fate. How does the CC get removed from the pool? Filtration? I understand that I am adding more bleach so that there is more FC available to kill everything, but what happens to the CC next?
Len
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#8
Chlorine breaks down algae in several steps. In the first step it combines with the organic material to form combined chlorine (CC). In the second and sometimes third step the CC combines with another chlorine to break things down to something harmless (eventually).