FCC levels too high-- shock anyway?

Jun 19, 2013
7
Detroit, MI
My free chlorine has been high almost all summer. I have been keeping the chlorinator at 1-2 and have still been shocking weekly, except I missed last week. Yesterday, the FC level was still high.
I'm due to shock tonight, but not sure if I should.
The water looks crystal clear.
 
FC high means absolutely nothing. Why do you think you need to "shock" as you put it? Post us up a full set of test results please. Welcome to the forum--------feel free to enjoy pool school.
 
Welcome to TFP! :wave:

Assuming your chlorinator uses Trichlor tabs, you are running on borrowed time. Your Cyanuric Acid (CYA) level is likely high or increasing rapidly and that can lead to algae growth in the future, though you could get lucky as you apparently have been so far (perhaps your pool is poor in algae nutrients or you are using other products such as algaecides or phosphate removers).

If you do not have one of the recommended test kits already, you should get one. Either the TFTestkits TF-100 or the Taylor K-2006 where the TF-100 gives you more volume of reagents you use the most so is more economical (see Test Kits Compared). While waiting for the test kit, start reading the Pool School to learn more about how to maintain your pool.
 
Thank you. Here are my test results with a test kit I bought literally the day I posted.
Total Cl: >5
Free Cl/ Br: 10/20
pH: 6.8
Alk: 80
Cya: 120 (chem geek: you are right!)
Hardness: water test indicated hardness is not present (which would explain why the pool tiles are always falling off!)

I also did a test strip which had some varying results (it indicated hardness is fine) but I know enough to trust the test kit and symptoms over that.
 
If your CYA is 120 I assume you measured by using a dilute solution or did you use a pool store? Did you get the HTH 6-way kit at WalMart or other box store?

Either way, it is at least twice where it should be for a normal, chlorine managed outdoor pool. When your CYA is above 70 it is very hard to manage the pool. When it's above 100, it's almost impossible to add enough chlorine to make it effective. All of the chlorine you add become bound to the CYA and it is very ineffective at killing algae.

How cost effective and clean are your fill water sources? Are you on a well or need to truck in pool water?
 
Sunlover101 said:
Yes you're right. It's the HTH 6 way kit.
We use the hose for fill water, are not on a well. Live in a suburban area.
Why is my chlorine level so high?
Any idea what I should do to get it back to normal?
Actually, your FC level isn't too bad for your CYA level.

When the pucks dissolve, don't add any more and switch to bleach. Then you can control the FC level.

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You NEED the FC high to prevent algae due to the high CYA level. In fact, with a CYA of 120ppm you should never let the FC get below 8ppm or you are risking algae.

What you need to do is:
1. Replace 50-70% of the water to get the CYA in range
2. Stop using pucks and switch to bleach.
3. Go through the SLAM Process which requires the FAS-DPD chlorine test found in the Recommended Test Kits.
 
Thanks everyone! I have been doing some reading and I realize I have been clueless for the past 4 summers, which is why my CYA is so high and my water chemistry is out of whack.
I guess I'm going to have to bite the bullet and drain and refill.
So, my next question:
What is the best way to do this? I have a sand filter. Backwash/waste through the backwash hose into the street or the community drain behind the house?

Thanks!
 

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Sunlover101 said:
Thanks everyone! I have been doing some reading and I realize I have been clueless for the past 4 summers, which is why my CYA is so high and my water chemistry is out of whack.
I guess I'm going to have to bite the bullet and drain and refill.
So, my next question:
What is the best way to do this? I have a sand filter. Backwash/waste through the backwash hose into the street or the community drain behind the house?

Thanks!
Waste setting. Sewer is the safest bet. Around where I live, they get very nasty about what goes into storm drains, because it all heads to the nearest creek, then river, and then to the ocean, untreated.
 
What type of pool do you have. The answer can effect how you should drain. Add your pool specs to your signature. And, congrats on sticking around and reading and learning. In very short order you will feel like a pro because you'll be in control of your pool. Don't forget to order a good test kit if you want to fully take control!
 
Ok, I added what I can remember as of now to my signature.
I need to buy a new backwash hose because mine broke today. I am going to get one long enough to reach the street. Anything else I should know?
How about using sewer vs (the other water option coming from the outside spigots) to refill?
And, yes I will bite the bullet and purchase a decent test kit. If I can make it to a pool store tomorrow, should I go ahead and buy these items there (providing they have the right kind) or is it cheaper to buy online?

Also, we are having people over to use the pool on Sunday, Monday, and Tuesday coming up. Tomorrow is Wednesday. if the water is currently clear and chlorine level higher than 10ppm (but there is visible dirt on the walls and floor of some areas of the pool that the sweeper doesn't seem to want to pick up), should I leave it alone for a week and just make sure chlorine stays high so algae does not develop, or try to drain, refill, rebalance, and reheat in the next three days?

Thanks again.
 
You will not likely find one if the recommended test kits locally, order it.

Amazing that so many people come here with plans for people to use the pool and then want the miracle fix in a few days ... telling people they can not swim is never an option.

As long as the pool is clear, and you keep the FC up around 10ppm, it should be safe.
 
Well truly, since I have been the one taking care of the pool, I selfishly want to enjoy it with friends. And in my defense, I did not really know I had an issue until yesterday.
I am glad I seem to have it figured out, though. Thanks to this great site.
 
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