Big drop in FC and CYA in a week...

jamjam

Well-known member
Jun 25, 2020
668
NY
Pool Size
25000
Surface
Vinyl
Chlorine
Salt Water Generator
last week:
FC 6.6
CC 0
CYA 30
PH 7.2
TA 50

Today
FC 1.2
CC .2
PH 7.4
CYA <30
TA 50

We have had 3 days over 90 in a row and i have had the solar cover off - Today I added some liquid bleach to give the FC a boost and 5 lbs of CYA -

prior to this mini heatwave i pumped to waste about 2 inches of water after heavy rain fall. Should I be running my filter more to generate more chlorine - or was this drop likely due to the CYA loss and the 3 days of blazing sun?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
44,355
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
That low of CYA with a SWCG in an outdoor pool without an autocover is dancing with algae. I would at least raise the CYA to 50 or 60 ppm and use 10% of the CYA as your target range.

Use liquid chlorine to raise your FC to target. Use the SWCG to maintain that.
 

jamjam

Well-known member
Jun 25, 2020
668
NY
Pool Size
25000
Surface
Vinyl
Chlorine
Salt Water Generator
I added 5 lbs of CYA and will test again in a few days - I will test my FC again later today after adding the bleach - will keeping the solar cover on help maintain FC?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
44,355
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
will keeping the solar cover on help maintain FC?
It will. But be sure to take it off for a few hours every few days. That way any CC buildup can burn off.
 

jamjam

Well-known member
Jun 25, 2020
668
NY
Pool Size
25000
Surface
Vinyl
Chlorine
Salt Water Generator
k i got the FC up to 1.8 with the bleach - ill see what my CYA is in 2 days and then adjust from there - i guess i should be testing every day for a while from there to dial in my SWCG run time
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
44,355
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
A FC of 1.8 ppm is way below any minimum. You need to get it to at least 5 ppm to let the SWCG take over.
 

jamjam

Well-known member
Jun 25, 2020
668
NY
Pool Size
25000
Surface
Vinyl
Chlorine
Salt Water Generator
k - even if the CYA is still low? I was waiting for it all to dissolve before upping it more - or am i good to add it now?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
44,355
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Add it now. Algae does not care - at that level FC you can get it quick.
 

jamjam

Well-known member
Jun 25, 2020
668
NY
Pool Size
25000
Surface
Vinyl
Chlorine
Salt Water Generator
FC was 4.4 this morning - i am going to wait until tomorrow to test the CYA
 

Enjoying this content?

Support TFP with a donation.

Give Support
Thread Status
Hello , This is an inactive thread. Any new postings here are unlikely to be seen or responded to by other members. You will get much more visibility by Starting A New Thread