Fc will not go up

bhubb

Well-known member
Jan 4, 2016
87
KS
Hello everyone - I installed a pentair vsf and a new pentair tr100 sand filter and while everything was down for the 3 unexpected days it took my pool went murky and now I can’t raise fc. I added 5 bottles of 10% and fc read 3 (previously zero). I added 8 more jugs a few hours later and now I am still at 3. I understand it is attacking the algae most likely but how am I to get it to 24? Seems like I have to add 30 more bottles.

cya is 50 with automatic cover usually on

I understand I gotta get over the hump but does it usually take this much? I have never had this issue
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,637
Laughlin, NV
Did you test your CYA recently?

Do the following:
Raise your FC in the water using enough liquid chlorine to get to 10 ppm using PoolMath. Circulate the pool for 15 minutes. Test FC and CC. Report back here.
 

bhubb

Well-known member
Jan 4, 2016
87
KS
Did you test your CYA recently?

Do the following:
Raise your FC in the water using enough liquid chlorine to get to 10 ppm using PoolMath. Circulate the pool for 15 minutes. Test FC and CC. Report back here.
Yes I tested my cya 3 days ago. My swg was not generating after I installed pump. They said it was phosphates or dirty cell. I cleaned cell (didn’t look scaled) but salt readings went from 3300 to 3600 so must have been some scale. I currently have swg off and adding liquid chlorine now. Will report back in a few when get to 10. Also my powder is expired by 8 months but can’t imagine it is bad as it is stored properly but I do need to order new
 

bhubb

Well-known member
Jan 4, 2016
87
KS
Ok I added way more to get over hump and added 8 bottles based off my made up math and am at 25 now so I guess I will see what it is in am and how much it clears. This pump moves some serious water and hoping this filter is huge upgrade. Oversized it as much as I could
 

bhubb

Well-known member
Jan 4, 2016
87
KS
Do you have the K1000? Use the OTO next time you test as well to see what depth of color you get on it.
I have it but never used it. I think I am slightly colorblind and it is hard for me to tell color matching tests.. wife and I see 2 different colors. Will have to try it tomorrow in daylight
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,637
Laughlin, NV
OK -- from your description it sounded like ammonia. But if you are holding chlorine, you either did not have it or have defeated it.

Be sure to change your signature with your new equipment.

The K1000 is just to see if it is showing chlorine when your FAS-DPD is not.
 

bhubb

Well-known member
Jan 4, 2016
87
KS
Water cleared up overnight. Fc down to 3 so back to 24. Tested cya again to verify and am not getting any.. very odd bc I added 10lbs a week or 2ago and it was reading 50 a few days ago.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,637
Laughlin, NV
The CYA was converted to ammonia. That is why you had to add so much chlorine to get a FC reading.

Add enough CYA to raise it to 30 ppm.