My FC and CC are very similar

[Jmcgugan]

First of All, please allow me to thank everyone on here so far! The inforamtion that I’ve gathered in the last week has been impeccable! Over the first two days of having my pool opened my FC and CC have been quite similar. I’m using the Taylor test kit—Unsure if it’s something that’s up with the testing, or maybe the numbers don’t lie. (I was going to take it to a pool store this week just to confirm). I’m doing a OCLT starting tonight. Here are my results over the last two days:

23 May 3:00 pm
FC: 1.2
CC: 1.2
pH: 7.4
TA: 140
CH: 320
CYA: 0

Added 2 Gal Stabilizer

24 May 10:00
FC: 0.8
CC: 0.6
pH: 7.5
CYA: 50

Added 1.0 Gal Bleach (12.5%)

24 May 5:34 p.m.
FC: 1.4
CC: 1.4
pH: 7.4
TA: 170
CH: 300
CYA: 35

Added 1.0 Gal Bleach (12.5%)

24 May 10:00 p.m.
FC: 3.6
CC: 3.4

This is year 2.5 of having the pool. Last year I had a very hard time with CYA levels (And dealt with a Major pool store—Les...) and the color of the pool. It is still a bit green right now—One of the reasons I opted for a OCLT. I’m hoping to SLAM it over the course of this week (if required) and have a bit more control over the pool this year. I vacuumed 2x this weekend so far, and it finally looks CLEAR, but still an off color. I’ll get there!

 

[ajw22]

Don’t bother taking your water for a pool store test. It will prove nothing and just confuse you. Trust your test results.

Do your Overnight Chlorine Loss Test but based on your FC and CYA you likely have algae.

I suggest you read ABCs of Pool Water Chemistry and study the FC/CYA Levels.

 

[Jmcgugan]

Thank you @ajw22! I was just confused by the fact that FC and CC were similar (and sometimes CC was higher), but you’re right—I should trust the test kit (and the process). My OCLT resulted in a loss of 1.8ppm FC. I started SLAMming it this morning! Thanks!

 

[zea3]

To save on reagents use a 10ml sample and count each drop as .5

 

[Richard320]

You've got a proper test kit, you've got us, you'll clear it.

morebleach

• Richard320
• May 20, 2014

 

[Hootz]

Regardless if you have algae or not your fc levels are too low. A cya level of 50 calls for an fc target of 6-8 ppm. Keeping your FC-cya ratio is one of the core principles here.

 

[Jmcgugan]

I feel like pool math is wayyyy off. It’s only telling me to add 4gal of 12.5% bleach to raise the FC from 4.0 to 20. It’s a 25k Gal pool With a CYA of 50.

 

[Donldson]

What looks wrong? One gallon of 12.5% will raise a 25,000 gallon pool 5 ppm.

 

[Jmcgugan]

I guess my numbers don’t replicate that. My FC at 8 p.m. was 1.4. I added 6 gal of 12.5% bleach and I checked it at 11 p.m. and my FC was only 4.0. My CC was over 4.0 though.

 

[IceShadow]

I guess my numbers don’t replicate that. My FC at 8 p.m. was 1.4. I added 6 gal of 12.5% bleach and I checked it at 11 p.m. and my FC was only 4.0. My CC was over 4.0 though.

Either the bleach was old or you have stuff growing in the pool. The latter is more likely. If you’re SLAMming keep adding bleach to get to 20 ppm. Your FC drop should get less and less as you go.

As zea3 said above,use a 10ml sample and one big scoop of powder. Each drop then is 0.5ppm. That’s precise enough for your needs. Saves reagents.

 

[Jmcgugan]

I clorinated the heck out of it today. Finally got a CC at 0.5!!!! Going to check OCLT one more time tonight. FC is currently at 8.5 and CC is at 0.5. Looks like the last bit of algae “carcasses” are sitting at the bottom (Vacuum tomorrow morning!)

I finally saw the increase in FC that @Donldson was talking about! 1 gal of 12.5 raised it 5 ppm! Took a little more time than I had anticipated and and a little frustration—but all part of the learning process!

Thank you all for your help (So far)!