Mid day update: FC is now at 3.0, so has dropped 1.5 since 6:30 this morning (6 hrs ago). Thinking stabilizer isn't enough yet?
Chlorine loss & pH level
- Thread starter DOMO
- Start date
- May 3, 2014
- 59,633
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
What CYA level have you targeted with your additions? If you put the powder in the water, the CYA is there.
Be sure to have your FC at target level based on your expected CYA. Your FC was too low to start with this morning.
Be sure to have your FC at target level based on your expected CYA. Your FC was too low to start with this morning.
hi. i'm targeting 40-50 CYA so was shooting for 6 on FC. I added bleach to bring it from 4.5 to 6.0 this morning, but it continues to lose 1.5 FC every 12 hrs
- Apr 23, 2017
- 2,400
- Pool Size
- 22000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Are you using pool math? How are you or did you add the CYA to water? What is the bleach percentage (6, 8.25,10)?
When adding bleach are you shooting for your target according to Chlorine/CYA Chart? Knowing there will be somewhere between 1.5 and 2 loss daily make sure you are adding enough to cover the loss. Stock up on bleach!!
Looking forward to response...
When adding bleach are you shooting for your target according to Chlorine/CYA Chart? Knowing there will be somewhere between 1.5 and 2 loss daily make sure you are adding enough to cover the loss. Stock up on bleach!!
Looking forward to response...
- May 3, 2014
- 59,633
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
If you raised your FC to 6 this morning, but it is now 3 after 6 hours, you most likely have something in the water using up the chlorine.
Run a Overnight Chlorine Loss Test tonight.
Run a Overnight Chlorine Loss Test tonight.
sorry, let me clarify, I raised it to 6 last night around 6:00 PM (after having added the stabilizer during the afternoon). it was at 4.5 at 6 a.m. today and now at 3.0 at 1:00 pm. Not sure what could be in the water as all other levels are good, it's a FG pool with no stairs or other places for algae to hide, except for light niche, which I already checked. I was under the impression that the chlorine was being eaten up by the sun since the CYA was so low (10-20).
- May 3, 2014
- 59,633
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
DOMO,
1.5 FC loss over 12 hours is acceptable, especially during the hottest part of the day. Have you taken a CYA test after your latest addition?
1.5 FC loss over 12 hours is acceptable, especially during the hottest part of the day. Have you taken a CYA test after your latest addition?
Hi. Thanks for the replies. I haven’t tested CYA since yesterday as the last suggestion I received was to wait 2-3 days, but I can test later today as I’m not home at the moment.
If 1.5 FC loss is ok over 12 hours, that would mean I’d lose 3 over 24 hrs, which is about 44 oz daily to maintain target. That’s about $45/month in bleach which still seems high. Are people spending that much in daily / monthly bleach costs?
If 1.5 FC loss is ok over 12 hours, that would mean I’d lose 3 over 24 hrs, which is about 44 oz daily to maintain target. That’s about $45/month in bleach which still seems high. Are people spending that much in daily / monthly bleach costs?
- May 3, 2014
- 59,633
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Not true. Unless you have organics in your pool (algae) you will not lose more than 1 ppm FC over night. Should in reality be 0.
Run a Overnight Chlorine Loss Test tonight.
MannyT
0
He said he loss 1.5 between 6pm and 6am. He then raised it to 6 and then by 1pm it was down to 3ppm. I sounds like he has algae.
- Apr 23, 2017
- 2,400
- Pool Size
- 22000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
mknauss is the expert on this! What he says overrides anything I say for sure. His advise will get you where you need to go and there may be other things going on that he needs to verify by having you do the testing. Its really east to do! If you are not sure how to to the overnight test read this...
Overnight FC Loss Test (OCLT)
Overnight FC Loss Test (OCLT)
My thoughts exactly.
@DOMO, you cannot test within a few hours of adding chemicals. You should be recirculating for a while, before doing any test. Many do this for +/-24 hours.
Rain here was overflowing my pool depleting my CYA and Chlorine. It took almost 6 hours to just to dissolve the 5lbs of CYA.
Hi all, Thanks for all the replies. I am unable to do an OCLT test as I won't be home tonight, but I did this for all intents and purposes last night as I took a reading after the sun was off the pool and chemicals hadn't been added and FC was 6.0, then did it again early this morning and it was 4.5, so a loss of 1.5 (close to the 1.0 in the OCLT instructions).
On the subject of algae or something organic, please help me understand where that could be, as I went through this subject last Summer. I have a FG pool with no railings, etc, so the only spot for algae to hide is in the light niche and as mentioned, that's clean.
As for testing the CYA, people have said it could take days for that to come up to level after adding stabilizer, and someone else asked me to re-test for it hours later, and today I'm seeing requests to test it again (after treating it yesterday), but also not to do this for +/- 24 hrs. I'm confused!! That said, I just re-tested it for the heck of it, and I don't see a change, as I fill the entire CYA test vile and still see the dot.
Phew!!
On the subject of algae or something organic, please help me understand where that could be, as I went through this subject last Summer. I have a FG pool with no railings, etc, so the only spot for algae to hide is in the light niche and as mentioned, that's clean.
As for testing the CYA, people have said it could take days for that to come up to level after adding stabilizer, and someone else asked me to re-test for it hours later, and today I'm seeing requests to test it again (after treating it yesterday), but also not to do this for +/- 24 hrs. I'm confused!! That said, I just re-tested it for the heck of it, and I don't see a change, as I fill the entire CYA test vile and still see the dot.
Phew!!
Well, according to pool math.
"CYA Goal: 30 to 50
Add 27 oz by weight or 28 oz by volume of stabilizer or add 69 oz of liquid stabilizer.
To lower CYA you replace some of the water with new water.
Note: It can take solid stabilizer 24 to 48 hours to dissolve."
How big of a bottle of stabilizer are you buying?
"CYA Goal: 30 to 50
Add 27 oz by weight or 28 oz by volume of stabilizer or add 69 oz of liquid stabilizer.
To lower CYA you replace some of the water with new water.
Note: It can take solid stabilizer 24 to 48 hours to dissolve."
How big of a bottle of stabilizer are you buying?
Where are you located at DOMO? What is the weather like?
Too low CYA, your chlorine will burn off fast if in sunlight and it is hot. If your CYA is reading 15ish, you are going to need about 4lbs.
Dump into a sock, and suspend it in front of return jet. This method seems to be best. I however, put it in the skimmer.
Also, 5-10 more CYA is not going to hurt. But you have to get it to where it is actually reading in the vile.
Too low CYA, your chlorine will burn off fast if in sunlight and it is hot. If your CYA is reading 15ish, you are going to need about 4lbs.
Dump into a sock, and suspend it in front of return jet. This method seems to be best. I however, put it in the skimmer.
Also, 5-10 more CYA is not going to hurt. But you have to get it to where it is actually reading in the vile.
- May 3, 2014
- 59,633
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Early in this thread you discussed adding very small amounts of CYA at a time. How much have you added overall since you started? If you have not added at least 40 oz by weight of the powder you are not yet were it will register in your test.
When you add CYA, use the sock method. Once all the powder is dissolved out of the sock, wait at least 24 hours prior to testing CYA. However, you can assume it is in the pool as you put it in the pool and it does not react with anything.
Algae is not always visible. If you can see it, it has overwhelmed the pool. Just because you cannot see algae doe not mean you do not have it in your pool. The Overnight Chlorine Loss Test is the best confirmation of whether you have active algae or not.
When you add CYA, use the sock method. Once all the powder is dissolved out of the sock, wait at least 24 hours prior to testing CYA. However, you can assume it is in the pool as you put it in the pool and it does not react with anything.
Algae is not always visible. If you can see it, it has overwhelmed the pool. Just because you cannot see algae doe not mean you do not have it in your pool. The Overnight Chlorine Loss Test is the best confirmation of whether you have active algae or not.
Hi mknauss. Thanks for the reply and additional info.
Understood on not seeing algae, all I'm saying is that my understanding of algae and the type of pool I have, etc. I have always been told that's unlikely.
At this point, I have added about 18 oz (by volume) of granulated stabilizer, it sounds as though I need another 20 oz by volume? Or what is the equivalent of what I've added and how much more I need, by weight? I am cautious to not overdo it on the stabilizer as last year my CYA was through the roof and that created a whole new host of challenges.
Thanks!
Understood on not seeing algae, all I'm saying is that my understanding of algae and the type of pool I have, etc. I have always been told that's unlikely.
At this point, I have added about 18 oz (by volume) of granulated stabilizer, it sounds as though I need another 20 oz by volume? Or what is the equivalent of what I've added and how much more I need, by weight? I am cautious to not overdo it on the stabilizer as last year my CYA was through the roof and that created a whole new host of challenges.
Thanks!
- May 3, 2014
- 59,633
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Not sure why you think you cannot get algae with your type pool. ALL pools can get algae.
You need at least another 24 oz by volume of CYA added before it will show on your test equipment.
You need at least another 24 oz by volume of CYA added before it will show on your test equipment.
Re: Chlorine loss & pH level
In DOMO's last reply mentioned basically doing the OCLT last night and FC dropped 1.5. Water is clear but that is not a true indication as you have mentioned. All the tests done indicate after adding bleach, the FC levels have dropped.
CYA most definitely needs to be brought up. No word on % of bleach being used either.
- - - Updated - - -
If you are measuring in a measuring cup or scoop, you will need another 42 oz by volume of stabilizer.
You are being a bit too cautious. With your pool size, it takes approx 1 pound of stabilizer to raise the CYA level 10ppm. Also, 50ppm is not too high. It is on the high side but within range.
In DOMO's last reply mentioned basically doing the OCLT last night and FC dropped 1.5. Water is clear but that is not a true indication as you have mentioned. All the tests done indicate after adding bleach, the FC levels have dropped.
CYA most definitely needs to be brought up. No word on % of bleach being used either.
- - - Updated - - -
If you are measuring in a measuring cup or scoop, you will need another 42 oz by volume of stabilizer.
You are being a bit too cautious. With your pool size, it takes approx 1 pound of stabilizer to raise the CYA level 10ppm. Also, 50ppm is not too high. It is on the high side but within range.