Test results - am I OK with Chlorine and Stabilizer?

BelLa's Pond

LifeTime Supporter
Apr 13, 2010
44
Phoenix, AZ
Test Results (using TF Test Kit):

FC 4
CC 0
TC 4
PH 7.7
TA 130
CH 450
CYA 95
I just dumped a gallon of chlorine in the pool last night. It has been 3 weeks since I added 5 pounds of stabilizer.
My main concern has been with chlorine. I am using BBB method, liquid chlorine (10%), etc. The temperature here in Phoenix is now between 105 and 115. I have been adding about 2.5 gal. of chlorine per week. The last 2 times I have added stabilizer (CYA 99%), I still had to add more chlorine within 3 days. Is this normal?
If so, am I not better off paying $15 a week for chlorine instead of $30 per week for chlorine and stabilizer? Up until recently, my CYA reading has been 0

Also, I have not done the CH test before because I have a fiberglass pool. Is 450 CH something to take action on?

The pool is crystal clear. Main debris coming from dirt surrounding my unlanscaped yard, dog hair, moderate amount of tree/bush debris. I skim surface every day. Hayward pool cleaner in good working order (running 4 hours a day) with leaf catcher. I have backflushed once in 3 months.

Thanks for all replies!!!!
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,880
Silver Spring, MD
Your CYA/stabilizer level is too high and your FC level is too low. For CYA around 95 you want to keep FC between 7 and 15 at all times. Your best option is to replace some water to get your CYA level down to around 60 or 70. You should also do an overnight FC loss test to see if you have any algae growing in the pool (which can happen even when the water is clear).
 

BelLa's Pond

LifeTime Supporter
Apr 13, 2010
44
Phoenix, AZ
Thanks for the reply. I realize now the mistake I made of putting stabilizer the 2nd time. I will go ahead and try replacing water and do another FC test tonight.

How about the issues of quantity of chlorine I'm adding and CH level?
 

loughps

Well-known member
Apr 26, 2009
221
Northeast Ohio
I still had to add more chlorine within 3 days. Is this normal?
Chlorine is consumable. If you are manually adding liquid chlorine, you should be testing nightly and adding enough chlorine to be above your minimum chlorine level by the next evening. Many folks lose 3 - 4 ppm FC per day. But to answer your question, adding chlorine DAILY is the norm when manually dosing the pool.
 

loughps

Well-known member
Apr 26, 2009
221
Northeast Ohio
When I put your numbers into the pool calculator, it says that you're risking calcium scaling. You could lower your pH down to 7.5 or lower your TA, or both to get your CSI number down, but let the experts weigh in on those suggestions because I don't have a fiberglass pool, nor high CH water like you're going to have in AZ. If it were mine, until I got an answer from the experts, I'd lower my pH to 7.5 and see what suggestions come back.

You could try a reverse osmosis treatment to get your CH down, but with proper maintenance, you can probably run at that high CH level and save the cost of the treatment.
 

BelLa's Pond

LifeTime Supporter
Apr 13, 2010
44
Phoenix, AZ
Thanks again for the replies.

I ran the tests 3 more times and tried to be more deliberate thinking maybe I'd made a mistake.

Yesterday's reading:

FC 0.5
Ph 7.8
TA 110
CH 400
CYA 60

I did the overnight FC loss test after my last post, and sure enough, FC came up 0.

I added a gallon of chlorine and the next day came up with FC 4, but that only lasted one day again.

I also replaced water over the last two nights by adding a total of about 4 " of water that had evaporated. I generally lose about an inch a day right now. Does this count as water replacement or do I need to drain???

Going back to FC, does this mean I need to shock? Or accept it as a normal loss and just keep adding chlorine?

My pool gets moderate use: 2 adults swimming daily for about an hour and one very active Labrador swimming about the same.
 

BelLa's Pond

LifeTime Supporter
Apr 13, 2010
44
Phoenix, AZ
I added some shock and some muriatic acid last night. Today the chlorine and Ph readings were perfect. Will run full tests tomorrow.

So should I expect to have to shock often?

Any input about calcium?

Thanks
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,799
San Dimas, CA (LA County)
BelLa's Pond said:
I added some shock and some muriatic acid last night. Today the chlorine and Ph readings were perfect. Will run full tests tomorrow.

So should I expect to have to shock often?

Any input about calcium?

Thanks
If you get rid of all the algae once and for all, and keep the FC above minimum for your CYA levels at all times, you may never have to shock again.

Your chlorine loss sounds a little high; could still be algae; could be low CYA and Arizona sun; the dog swimming doesn't help any either.

Calcium is going to be a problem. Your water is probably very hard, and you lose a lot of water to evaporation without getting much rainwater dilution. The water evaporates, the calcium stays behind. If you keep tabs on pH and TA, you can keep the CSI in the safe zone despite CH levels way up near 800. If you don't stay on top of it, it will start scaling - grow your own sandpaper on the pool walls!
 

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