Check my math please

[Mags®]

I've been having a issue with algae on the sides of the pool. Had one of those cheapo test that indicated chlorine was just fine. Came here and figured out that the test was useless and to get a real tester. Bought the recommended tester and got these results:

FC = 0 (might be the reason I have algae, ya think? :? )
TC = 2-4
PH = 7.6
CYA = 30
TA = 110

I read pool school and to bring the level of FC to the desired level I should add 80oz of 10% liquid chlorine I believe, but since I have algae, I need to shock and add 240oz of chlorine. Did I do that calculation right?

 

[RobbieH]

Um yea, FC of 0 means the algae welcome mat is out. CC of 2 to 4 (TC - FC) means algae has accepted and let itself in. Time to shock.

I'd say 16 is a good goal because that puts you a couple of points over your shock requirement. Keep an eye on it because I'm betting your FC drops a bunch in just an hour.

 

[crookm11]

I second what RobbieH says and want to add a little more to it. While shocking your pool you need to maintain your shock level until you pass the overnight chlorine loss test.
Perform the Overnight Chlorine Loss Test
How to Shock you Pool.

 

[Mags®]

Thanks for the help, just wanted to make sure I understood the charts correctly. I will remeasure in about an hour to guage the FC level of the pool. Thanks again for the help.

 

[RobbieH]

Post the FC and CC when you do. I like watching pools go from green to sparkly!

 

[Mags®]

Will do. Here is what it currently looks like. When I get the algae under control, I'm going to try the Borax thing out and see if I can get it to sparkle.

 

[Mags®]

1 hr later
FC = 3
TC = 4

 

[Mags®]

Not exactly where I need to be... :? Looks like time for more chlorine. I added 240oz of 10% already.

 

[Flotsam]

Keep at it !!

As the article says ... "Hit it Hard" !!

 

[Mags®]

I think the clorine I have is bad. Its been sitting out in the garage for about a year. I've added about 5 gallons so far and am barely at FC 3. I'll have to buy some fresh clorine tomorrow and try to get the Dang FC to raise into shock level!

 

[Flotsam]

Mags - check out ACE Hardware if they have a location near you. I get their 10% chlorine for $1.90 / gal. That's much better than the WalMart 6% bleach. You need to get your FC up to at least 16 -18 ppm and hold it there ... that will kill most of the organic critters floating around.

From the looks of your pix - you really don't have that big of a problem. Mine was NASTY GREEN !!! It took 10 days to get mine to look that good !!

You're headed in the right direction - use the Pool Calculator - test often - brush and backwash - read as much as you can in the Pool School - also ... patience and perseverance!!!

HIT IT HARD !!!!!

 

[Mags®]

Mags - check out ACE Hardware if they have a location near you. I get their 10% chlorine for $1.90 / gal.

So glad you recommended Ace considering I own one! :-D Going to go home at lunch and rehit it with some fresh clorine.

 

[Mags®]

TC 16

Helps when the chlorine you use is fresh. :?