CC higher than FC

[beaverplt]

Hi all, I opened my pool about two weeks ago and am having a hard time clearing up the water. It looks milky green and I suspect it has something to do with the chlorine levels. I just tested before this post with these results.

FC = 1
CC = 1.6
TC = 2.6
TA = 110
CH = 150
CYA = 50


My last test on Tuesday had similar results with the exception that CH was at 100.
I've never had a CC reading higher than the FC. I first thought my CH was too low, but at 150 it's the same as it was last year. Any help will be appreciated.

[swimdaddy]

Your CC is high because your chlorine in combining with something (algae, bacteria, organic stuff). You need to get your FC up to "shock" levels according to the best guess chart for your CYA level and keep it there until you are able to hold chlorine overnight. Use bleach, 8.25% strength from walmart will raise your FC up about 3 ppm or so? (Sorry, my bleach calculator on my computer doesn't seem to be working!)

As far as your CH, for a vinyl pool you really don't need to worry about it, unless it is way too high, which your is not.

The one number you didn't post is your pH. That's an important one too.

[beaverplt]

Ooops. forgot to list PH. It was at 7.2 at testing. Probably a little higher this morning. It makes sense now. There is a fair amount of organic debris in the pool that snuck under the cover. I've got 12.5% shock ($2.49 a gal at Menards) I've got the pool calculator bookmarked so I'll keep cleaning the pool and keep the FC up there until things clear.

Thanks so much.

[FormerBromineUser]

Your shock level is 15 for FC. Get it clear!

Here is the link to the best guess chart:
http://www.poolsolutions.com/gd/best-guess-swimming-pool-chlorine-chart.html

Once you pass the overnight test, I would aim for an FC of 6. 3 is your absolute minimum. I would never let it get below 4.

[beaverplt]

Well there's nothing like heavy rains to mess up balancing the pool. My PH is out of whack this morning. The good news is my FC is 15, CC is .8. PH is high now, but I'll get that straightened out quickly. My last two passes with the pool cleaner brought up much less organic material. I'm making progress.

[FormerBromineUser]

Are you using a 25ml sample for your FC/CC tests?

[beaverplt]

I've always used 25 ml for testing chlorine. I've only used the 10 ml for the calcium test.

[FormerBromineUser]

That's fine. While you are at shock level, you might want to consider the 10ml. 30 drops vs 75 is a bunch, especially if you are testing a lot. Just a thought.

[JimK]

That's fine. While you are at shock level, you might want to consider the 10ml. 30 drops vs 75 is a bunch, especially if you are testing a lot. Just a thought.


At high FC levels I've even used a 5ml sample (1 drop = 1ppm) to save reagent.

For normal everyday testing I use a 10ml sample. I never use a 25ml sample for FC. IMO, unless you're running FC really low, the .5ppm resolution 10ml sample size offers is fine.

[beaverplt]

Being one of those people who has to have his checking acct balanced to the penny, I probably go overboard on wanting accurate tests. I took your advice today and went with 10ml samples

That being said, I'm confused today. My water is still a cloudy light green. I'm not stirring up much organic material when I brush or run the pool cleaner.
My readings look right to me. Am I being impatient???
FC= 9
CC=.5
TA = 100 - 150. (my last 25ml test was 110)
CH= 150
PH = 7.0
I'm assuming my CYA is still around 50

[JimK]

You need to keep FC at shock level until all 3 of these conditions are met;

1. Water is clear, no visible algae
2. CC is .5 ppm or less
3. Overnight FC loss is 1ppm or less.

Right now your FC is too low. Shock level for 50 ppm CYA is 15.

[FormerBromineUser]

JimK is absolutely correct. I was just about to say the same thing! I'm glad your CC's are coming down.

Can you raise FC to shock level more than once a day? The more you keep it at 15ppm, the faster it will go.

Do you have a sand filter? You could try adding some DE to it. I can send you a link about how to do it if you're interested.

[swimdaddy]

Agreed. Fighting algae without getting to shock levels is sort of like fighting a large house fire with a garden hose. You will put out some flames, but your house will still burn down. Bring in the big guns and put it out!

[Anonymous [GDPR] European in the UK]

Although you are a "tester" the most important part you should deal with is adding bleach, lots of bleach very regularly get it up around 20ppm+ and maintain it there until it goes all nice and clear again. Then begin the balancing or summer will be over.

[beaverplt]

JimK is absolutely correct. I was just about to say the same thing! I'm glad your CC's are coming down.

Can you raise FC to shock level more than once a day? The more you keep it at 15ppm, the faster it will go.

Do you have a sand filter? You could try adding some DE to it. I can send you a link about how to do it if you're interested.

I can add bleach in the morning before I leave for work and again when I get home. Obviously, I'll test each time. What does DE do for a sand filter? I'm always willing to learn something.

[JimK]

I can add bleach in the morning before I leave for work and again when I get home. Obviously, I'll test each time. What does DE do for a sand filter? I'm always willing to learn something.

DE helps the sand filter out finer particles. You have to be careful that you don't add too much and clog the filter. I believe you add a little at a time until filter pressure goes up 1lb. Btw, I have no experience with sand filters. I've only ever had a DE filter.

Does someone else here have the link to the DE procedure for sand filters?

[FormerBromineUser]

Here are the step-by-step directions:

http://www.poolforum.com/pf2/showthread.php/3742

You can buy 25# of DE at Home Depot for about $20 and it will takes years to use it all up! Just make sure it is "diatomaceous earth" for pools. Pooltime is the brand that Home Depot carries.

[JimK]

Here are the step-by-step directions:

http://www.poolforum.com/pf2/showthread.php/3742

You can buy 25# of DE at Home Depot for about $20 and it will takes years to use it all up! Just make sure it is "diatomaceous earth" for pools. Pooltime is the brand that Home Depot carries.

Thanks. I figured you would have it. ;)

[swimdaddy]

I learned the hard way that you have to WAIT after adding DE to see how much the pressure will rise. Add a little bit, then wait 20 minutes to see if your need to add more. Last summer I stood there adding DE like a mad man until the pressure rose 1 lb, and then I came back that evening to find the filter completely clogged.

[beaverplt]

So I've gone a week keeping my FC above 20 and still have the milky green/brown water. It seems like I'm getting a lost of dead algae (light brown water) out when I backwash, so I'm not sure that the filter is the problem. But after giving it a week, I'm going to try the DE. I did find that my local Ace Hardware carries 12 lb boxes of it for about $12.

[FormerBromineUser]

DE can help your filter out. Btw, how often were you testing and bumping the FC back up?

[swimdaddy]

If the DE doesn't work, try adding a little bit of polyquat algaecide. Not only is it an algaecide, but it also acts like a clarifier, clumping smaller particles together, which are more likely to get stuck in your filter. You don't have to use much, I bought a bottle recommended on the Pool Solutions site 2 years ago, and I have used it twice, only putting in 5 ounces each time, and it cleared my pool overnight, and within a week crystal clear. It will drop the FC levels so you have to plan on that.

[beaverplt]

in the morning before work and at night trying for 12 hrs apart. It seems I'm adding shock more often at night than in the morning. Maybe due to sunshine? I haven't tested tonight yet, but it'll be interesting to see what 3 inches of rain did to the numbers.

Update. Just tested FC, CC, and PH. PH stayed at 7.2, CC stayed at .5, but FC went from 20 down to 13.5 in the 24 hrs. (I didn't test this morning with the storms.

[FormerBromineUser]

Yup. That's UV that causes the difference. Maybe you can sneak in one more test and add as soon as you get home from work?

[beaverplt]

Got some DE into the pool this afternoon. Went exactly as described. Pressure went up one lb with the 1/3 cup. As an aside, it seems odd that the smallest amount I could buy is ten pounds, yet I only needed 1/3 cup. I'm thinking I'm set for a while. One other note, don't use your wife's nice measuring cups. They're not harmed, but you might be.

[FormerBromineUser]

Hahaha! Yup, better get your own measuring cups!

My dedicated pool maintenance supplies include a 2Q and a 1C plastic measuring cup, a toothbrush, a pot scrubber, a scotch sponge with delicate scouring pad, a plastic turkey baster, a roll of paper towels, a plastic long-handled spoon, and 2 buckets: one small, one large.

You can include the box of DE in your will. It may last longer than you will! Cheap, though, and worth it.

[JimK]

Lol!

[swimdaddy]

I bought 2 huge boxes of DE that my children's children will cherish. Hah! BTW, what's the turkey baster for?

[FormerBromineUser]

Hahahaha! I use the turkey baster to shoot chlorine-rich water into my light niche on occasion. I don't take the housing all the way out; I just unscrew it enough that I can get the stream from the baster into the niche.

[JimK]

Hahahaha! I use the turkey baster to shoot chlorine-rich water into my light niche on occasion. I don't take the housing all the way out; I just unscrew it enough that I can get the stream from the baster into the niche.

Good idea. :)

[swimdaddy]

Yes, nice thinking.

[beaverplt]

I apologize for not following up. My pool is now crystal clear. I did two applications of the DE. It had been a long time since the filter had been "cleaned", I thought a second treatment wouldn't hurt. Thanks so much for all the help. I love this forum. BTW, Anyone need some DE?

[FormerBromineUser]

Excellent!!!!! Thanks for the update.... And the offer... Hahahaha!