Hi Alk Well Water Supply Woes...

[Fungi]

Don't try and keep the TA at 80 ppm. If the pH tends to rise, let the TA drop (from your acid addition that lowers both pH and TA) to 60 ppm and see if the pH is more stable.

As for your CC being high, it will be high after a soak, but if you measure before your next soak and still have it be around 1 ppm or higher, then that's strange. Yes, the higher CYA level will make the chlorine slower to oxidize the bather waste, but at higher spa temperature it still should have taken care of that in a day. This is especially strange since a working ozonator should have also dealt with the combined chlorine. Something is odd here unless you've been measuring the CC too soon after a soak. Perhaps the meter isn't as good as claimed with respect to FC vs. CC -- you can use a FAS-DPD chlorine test for comparison (if you have access to one).

Hi Chem Geek!

Thanks for your support man. I will add more Muriatic Acid when the PH goes to 7.9 within a few days. I will continue to take measurements and log the results. I will ignore the CC after a soak and only calculate it when I open the tub from now on. The numbers directly under the date are the "just opened" readings. So I got the following for the last few days.

0.93, 0.00, 0.94. The other ones were immediately following a dip or just after adding bleach. Also I have not shocked to 12ppm with bleach yet.

If it is a measurement error, could I benefit by ordering a new set of drops, just to have something to compare to what I currently have? The cost is not an issue for me. As for the accuracy of the meter. Sure it's a possibility, but as far as I know it uses the same drops as a visual version drop tester. I am under the assumption I could hold my test tube up to a visual chart for comparison, but I don't have one. lol

I know the ozonator is working because the smell of a lightening storm is STRONG when the lid is lifted after sitting overnight. I don't have access to any other test equipment, nor do I know anyone else with a tub.

I really appreciate your willingness to help me out here. You are awesome! Thanks, Jim

[Fungi]

Hi Chem Geek...

I hope this format is easier to read.

Tub: Jacuzzi J-345 50th anniversary model
Capacity: 458 gallons
Ozonator: Yes, restrictor removed by serviceman when the original clogged. 
Jets: 27
Power: 240vac @ 60amp, can run pumps and heater at same time. 
Circ Pump: Yes
Use: Year round, once every weeknight, sometime twice a day on W/E by two clean average size naked humanoids. 

Chlorine use. 
  Dips take from 1 to 1.5ppm.
  Tub takes from 5 to 6.5ppm overnight.
  Combined chlorine reads from .93 to 1.56 

6-28-2009 
New Fill No test results as digital tested not here yet. 

07-17-2009 
First complete set of readings from the digital tester. 
FCL  7.77
TCL  9.02
CCL  1.25
PH   7.6
ALY    72
CH   417
CYA    75
SI  0.30

07-27-2009
At opening...
FCL  1.85
TCL  2.78
CCL  0.93  
PH   7.7
Added 1 tbsp Chlorox. Took 20 - 25 minute dip. Added 3tbsp Chlorox. 
At closing...
FCL  3.61

07-28-2009
At opening...
FCL  0.69 (Tub used 2.92ppm)
TCL  0.69
CCL  0.00
PH   7.7
Added 3 tbsp Chlorox. Took 20 - 25 minute dip. Added 6tbsp Chlorox.
At closing...
FCL  6.42

07-29-2009
At opening...
FCL  1.25 (Tub used 5.17ppm)
TCL  2.19
CCL  0.94
PH   7.8
Added 2 tbsp Chlorox. Took 20 - 25 minute dip. Added 1/3 cup Chlorox. 
At closing...
FCL  7.30

07-30-2009
At opening...
FCL  1.46 (Tub used 5.84ppm)
TCL  2.66
CCL  1.20
PH   7.8
Added 1/4 cup Chlorox. Took 20 - 25 minute dip. Added 1/2 cup Chlorox.
At closing...
FCL  9.05

07-31-2009
At opening...
FCL  2.48 (Tub used 6.57ppm)
TCL  3.72
CCL  1.24
PH   7.8
Added no Chlorox. Took 20 - 25 minute dip. Added 1/2 cup Chlorox. 
At closing...
FCL  8.33

08-01-2009
At opening...
FCL  1.65 (Tub used 6.68ppm)
TCL  3.09
CCL  1.44
PH   7.8
Added 1/4 cup Chlorox. Took 20 - 25 minute dip. Added 3/4 cup Chlorox. 
At closing...
FCL  NA  Attepted to shock to 12ppm. Meter out of range (over 10.) 
         Didn't have distilled water to dilute and double reading. 

08-02-2009
At opening...
FCL  4.65 (Tub used approx. 7.35???)
TCL  6.21
CCL  1.56
PH   7.9 (Added 3tsp Spa Down, 95% dry Sodium Bisulfate, now 7.6)
Added 0 Chlorox. Took 20 - 25 minute dip. Added 1/3 cup Chlorox. 
At closing...
FCL  8.16
Will need to recheck check PH and ALK tonight.

I'm no longer reading TCL after we get out of the tub and only measuring it at tub opening. Still running too high.

Do you think I need to contact the mfg of the tester to see what they say about the combined chlorine CCL readings?

The last dip was at FCL of 4.65ppm. The wife says she smells bleach. My sniffer isn't so great. Is this normal using this method? Do we need to worry about hair color fading, natural and or treated hair?

Do you see a problem with the tub using from 5.0 to 6.5ppm overnight? Would the filters effect this. They are pretty old. I need to replace them anyway, but do you think they could be part of the problem?

Am I testing things in the right order? Do you see anything I'm doing wrong?

Testing for me goes like this.

Tub off and close since last use. Open lids to drain off water, then open both sides. Water sample bottle goes in to the tub away from the in's or outs of the recirc pump. With bottle held at elbow depth I squeeze and relax 3 or 4 times. I bring the tube up, open part facing up, screw on the top, and squeeze a little to clean out the top part.

With clean and dry test tubes I squeeze water from the sample bottle and stop just short of the fill line, then add a few drops to take it to the fill line. I place it in the machine and turn it on. After about a second it says blank. I press the button so the meter reads the blank water sample. I then add 5 drops each of the 2 first drop bottles. I do this by inverting the bottle completely vertical, hold them above the test tube and carefully add the drops being careful not to touch the sides. I do not shake the drop containers when doing this. As instructed I put on the lid, invert the test tube one time, then replace it in the machine and press the button so it reads. That's the basic idea.

I only test the following at tub opening... FCL, TCL, calculate CCL, PH, ALK, sometimes CH and CYA.

I test FCL before dips and after adding closing Chlorine.

I test PH within 10 minutes of adding Spa Down for minor adjustments, but also check the following day.

Looking forward to any good advice. Thanks, Jim

[Fungi]

What happened? Chem Geek? Nitro? Anyone? Why have you dropped me in the middle here? Have I offended or done something wrong? What's up? I'm simply trying to emulate your method. I'm no rocket surgeon but what the heck, I'm trying.....

[Fungi]

I called LaMotte Company. Told them of the troubles and the guy said he was sending me a new set of reagents for FC and TCL and a test strip pack for testing the same so I could compare them as a reality check. I am not sure why my CC will not go down. But soon I will at least know if it's the tub or the tester.

I'm not sure why I'm being shunned. I'm all ears if anyone would like to help me to understand this...

My CC is running from 1 to 1.5 every reading. Even after a 12ppm shock.

My tub is using between 5 and 7ppm every night.

I would appreciate it very much if any more experienced hot tub owners could chime in to help an old stupid fart keep a healthy tub for his sick wife. Thanks, Jim

[Nitro]

Sorry Jim. I must have missed your last post.

If your CC and/or Chlorine Demand (CD) are high, try using MPS (Non-chlorine shock). It works well at lowering them. Although keep in mind, after adding MPS your CC will test higher.

Read me link below about Chlorine Demand. It may help you.

[Fungi]

Sorry Jim. I must have missed your last post.

If your CC and/or Chlorine Demand (CD) are high, try using MPS (Non-chlorine shock). It works well at lowering them. Although keep in mind, after adding MPS your CC will test higher.

Read me link below about Chlorine Demand. It may help you.

Hi Nitro thanks for writing me. I have read that before. I'm at 40% as 4/10=0.4 or 40%. I already shocked to 12ppm using Chlorox but it didn't make any difference. Do you suspect non chlorine shock to do better?

The wife asked about the smell of bleach. Is this normal? Thanks, Jim

[Nitro]

Hi Nitro thanks for writing me. I have read that before. I'm at 40% as 4/10=0.4 or 40%. I already shocked to 12ppm using Chlorox but it didn't make any difference. Do you suspect non chlorine shock to do better?

Do you have an ozonator? If so, 40% may be as low as you're going to get. If not, you can lower it with bleach, but you have to keep shocking. One (or two, or three) shock may not be enough. FYI, if your CD keeps rising, it means you're not using enough Chlorine after soaks. If you use enough Chlorine after soaks, you really don't need to shock.

MPS works well at lowering CC/CD, and doesn't have any smell.

The wife asked about the smell of bleach. Is this normal? Thanks, Jim

What level is FC at when you soak? If it's above 6ppm, you're going to smell chlorine. Also, if your CC is high, you're going to smell Chlorimines, which is worse than Chlorine. Again, try MPS. It will help without having to shock with high levels of chlorine, many times.

[Fungi]

Hi Nitro thanks for writing me. I have read that before. I'm at 40% as 4/10=0.4 or 40%. I already shocked to 12ppm using Chlorox but it didn't make any difference. Do you suspect non chlorine shock to do better?

Do you have an ozonator? If so, 40% may be as low as you're going to get. If not, you can lower it with bleach, but you have to keep shocking. One (or two, or three) shock may not be enough. FYI, if your CD keeps rising, it means you're not using enough Chlorine after soaks. If you use enough Chlorine after soaks, you really don't need to shock.

MPS works well at lowering CC/CD, and doesn't have any smell.

The wife asked about the smell of bleach. Is this normal? Thanks, Jim

What level is FC at when you soak? If it's above 6ppm, you're going to smell chlorine. Also, if your CC is high, you're going to smell Chlorimines, which is worse than Chlorine. Again, try MPS. It will help without having to shock with high levels of chlorine, many times.

I do have an ozonator. It's running full speed with the restrictor removed by the service guy when it clogged. The CD isn't rising (I don't think.) I have been setting the FC at around 8 after each soak. it's around 2-3 the next night. So it's not high when we get in and it only take from 1 to 1.5ppm when we do soak. So it never goes to zero.

I was asking about a bleach smell not a chlorine smell. I guess that is the chloromines eh?

I was trying to avoid using non chlorine shock as it is measured by the meter making CC measurements inaccurate. Chem Geek said this... Thanks again for replying!

Non-chlorine shock (potassium monopersulfate, MPS) will measure as Combined Chlorine (CC) in most chlorine tests so will make your Total Chlorine (TC) reading higher than your Free Chlorine (FC) reading. Don't worry about that, though it does make using MPS more challenging. If you shocked with chlorine instead, then you wouldn't have these issues (and chlorine is a lot cheaper and pretty much just as effective and if you maintain your water chemistry properly you shouldn't need to shock much anyway).

[Nitro]

I do have an ozonator. It's running full speed with the restrictor removed by the service guy when it clogged. The CD isn't rising (I don't think.) I have been setting the FC at around 8 after each soak. it's around 2-3 the next night. So it's not high when we get in and it only take from 1 to 1.5ppm when we do soak. So it never goes to zero.

That could be the reason your CD isn't getting lower. I wouldn't worry about your CD then. As long as you're under 50% you're good.

I was asking about a bleach smell not a chlorine smell. I guess that is the chloromines eh?

Bleach smell IS Chlorine smell. They are the same thing. However, if it's strong smell, it's probably chloromines. Chlorine (Bleach) has a fresh clean smell.

I was trying to avoid using non chlorine shock as it is measured by the meter making CC measurements inaccurate. Chem Geek said this... Thanks again for replying!

The object is to keep CC low (<1 ppm), not to measure it. If you keep your CD low, and shock with MPS once a week and as needed, your CC will stay low. I don't even bother measuring my CC, I know it's low. With that said, MPS will not last very long in the tub (hours, maybe a day). Just measure CC once a week before you add MPS.

[Fungi]

I do have an ozonator. It's running full speed with the restrictor removed by the service guy when it clogged. The CD isn't rising (I don't think.) I have been setting the FC at around 8 after each soak. it's around 2-3 the next night. So it's not high when we get in and it only take from 1 to 1.5ppm when we do soak. So it never goes to zero.

That could be the reason your CD isn't getting lower. I wouldn't worry about your CD then. As long as you're under 50% you're good.

I was asking about a bleach smell not a chlorine smell. I guess that is the chloromines eh?

Bleach smell IS Chlorine smell. They are the same thing. However, if it's strong smell, it's probably chloromines. Chlorine (Bleach) has a fresh clean smell.

I was trying to avoid using non chlorine shock as it is measured by the meter making CC measurements inaccurate. Chem Geek said this... Thanks again for replying!

The object is to keep CC low (<1 ppm), not to measure it. If you keep your CD low, and shock with MPS once a week and as needed, your CC will stay low. I don't even bother measuring my CC, I know it's low. With that said, MPS will not last very long in the tub (hours, maybe a day). Just measure CC once a week before you add MPS.

Not sure how to know something is low if there is no way to measure it? The book that came with the tester goes into a lot of detail telling you how to measure CC, but doesn't go into any detail as to what would make reading CC inaccurate. Wow... just wow... Sadly hangs head shaking slowly mumbling to self. I'm so glad I now have the required tool to not be able to measure the required things to maintain a safe tub. Really I feel like either you guys aren't as good at this as I thought, or I'm being taken on a ride for someones entertainment.

I have spent hours collecting accurate information and it's been mostly ignored. I spent a great deal of time taking measurements that were of no value because of when they were taken or for some other unpublished technical reason.

I have tried to learn and provide feedback and all for nothing. Chem Geek tells me the ozonator should take care of all CC overnight, Nitro tells me the ozonator is causing the CC to read high. Chem Geek tells me not to use MPS as it makes CC readings impossible, Nitro tells me MPS will make the CC read properly the following day and Chlorox will not. Just go back and read this thread. Hey I have the upper hand here as I already stated I'm stupid. But I'm not telling people I can help them am I...

I have spent a lot of money and am only a little closer to resolving my problems then the day I found this forum. Is this really that diverse? I would have thought the process of taking care of a hot tub would have been nailed down and documented by someone in the year 2009.

[Nitro]

Fungi,

You're over thinking this. Don't get bogged down in detailing all your measurements. Step back a sec, and realize what's important.

There are only two things that are important. pH is in range (7.6 -7.8), and your Free Chlorine (FC) NEVER drops below 1 ppm. Everything else is just fluff.

Regarding Combined Chlorine (CC), don't worry about it. You can measure CC with your NOSE. I know when my CC get's up to 1 ppm, because I can start smelling Chlorimines. When (IF) that happens, just shock with either Chlorine or MPS to bring it back down. It's NOT unsafe to have CC high. It just smells bad.

Regarding Chlorine Demand (CD), I find this to be a far better indicator of your progress. If you keep CD low, your CC will also stay low.

Again, try not to bogged down, and start enjoying your tub.

[Fungi]

Fungi,

You're over thinking this. Don't get bogged down in detailing all your measurements. Step back a sec, and realize what's important.

Ok I'm no longer listing all the results of all the tests. I think there is something wrong. I will tell you I know the CD is between 5 and 6 every day. I am using about 1/2 cup Chlorox daily. Is that "normal"

There are only two things that are important. pH is in range (7.6 -7.8), and your Free Chlorine (FC) NEVER drops below 1 ppm. Everything else is just fluff.

In this regard I'm ok and have been since the beginning. I joke about never having chlorine when I open the tub, but honestly this has only happened a few times in the 2 years we have been using the tub. One time we were very ill and the tub wasn't opened for 48 hours.

Regarding Combined Chlorine (CC), don't worry about it. You can measure CC with your NOSE. I know when my CC get's up to 1 ppm, because I can start smelling Chlorimines. When (IF) that happens, just shock with either Chlorine or MPS to bring it back down. It's NOT unsafe to have CC high. It just smells bad.

In my case that will not help. I have a severe nasal blockage and can rarely smell anything.

Regarding Chlorine Demand (CD), I find this to be a far better indicator of your progress. If you keep CD low, your CC will also stay low.

What is low here. 5-6 seams high to me.

Again, try not to bogged down, and start enjoying your tub.

I'm enjoying it believe me. I just find it extremely irritating I can't get results other people, and even the book with my tester, say I should get. I only measure CC when I open it at night just before we use it. From all I have read this is the correct method. It's almost random. Bounces from 0.93 to 2.05, never lower or higher. Even after I shock with both methods I get really no change. I called the place that makes the tester. They sent me a new batch or bottles of reagent. These measure FC a little lower then the original, like about 0.1ppm lower. But the CC is still well above 1.

http://www.lamotte.com/pages/pool/colorqs.html

There you have it. Concise, no long lists of measurements, just my basic problem. I hope someone with similar issues can help me shed some light on this.

[Nitro]

Ok I'm no longer listing all the results of all the tests. I think there is something wrong. I will tell you I know the CD is between 5 and 6 every day. I am using about 1/2 cup Chlorox daily. Is that "normal"

Chlorine Demand (CD) is a percentage. 1 - (1st Day's FC) / (2nd Day's FC) I'm not sure where you're getting 5-6.

1/2 Cup (more or less) Bleach could be ok without use. With use, it's probably not enough.

What is low here. 5-6 seams high to me.

Again how are you getting 5-6?

I'm enjoying it believe me. I just find it extremely irritating I can't get results other people, and even the book with my tester, say I should get. I only measure CC when I open it at night just before we use it. From all I have read this is the correct method. It's almost random. Bounces from 0.93 to 2.05, never lower or higher. Even after I shock with both methods I get really no change. I called the place that makes the tester. They sent me a new batch or bottles of reagent. These measure FC a little lower then the original, like about 0.1ppm lower. But the CC is still well above 1.

.

I'm not convinced you're not getting the results everyone else is, but may be getting false readings.

If you're really worried about it, do a Super Shock.

1. Add 2-3 oz MPS and 2-3 cups Bleach. (depending on how irritated you are)

2. Let the jets run (without air) for an hour, uncovered.

3. Cover and let it sit overnight, without using.

4. The next day, open the tub and check FC only. (It should be >10ppm).

5. Let the jets run (with air) for 20 mins, cover and let sit overnight again, without using.

6. Continue steps 4 and 5 until your FC is around 3 ppm. (may take a few days)

7. Check CC.

Your tub will be clean as a whistle at this point. Meaning your CD should be at its baseline (whatever that is), and CC should be well under 1.0. If not, you may be getting false readings.

[Nitro]

The Super Shock may work, but I didn't know your CYA was so high (100 ppm).

My advice, REFILL!

[shovelhd]

What year is your J345? If it is not a 2009, your fill volume is not what you say it is. In 2009, Jacuzzi changed the shell configuration and added another 100 or so gallons. My 2005 J345 fill volume is 336 gallons. Check your owner's manual, and with Jacuzzi if needed. This could be screwing up your chemical load.

[Fungi]

Chlorine Demand (CD) is a percentage. 1 - (1st Day's FC) / (2nd Day's FC) I'm not sure where you're getting 5-6.

1/2 Cup (more or less) Bleach could be ok without use. With use, it's probably not enough.

I measure the tub before we get in and it's around 3ppm. The average chlorine used by us when we soak is around 1ppm. For me adding 1/2 cup raises chlorine 7ppm, My math says 3 - 1 +7 = 9. The tub uses 6 overnight so we're back to 3 the next night. So it's using from 5 to 6 ppm. If I add more wouldn't the values just go up.

Again how are you getting 5-6?

Ok this is just as simple, sorry for using the incorrect term. So the tub uses between 5 and 6 repeatably I was using this as the chlorine demand. I have tried to hit 8 as the target for chlorine when I add after a soak. I guess using your percentage method, 3/9=.33, 1-.33=.67 or 67%

I'm not convinced you're not getting the results everyone else is, but may be getting false readings.

If you're really worried about it, do a Super Shock.

1. Add 2-3 oz MPS and 2-3 cups Bleach. (depending on how irritated you are)

2. Let the jets run (without air) for an hour, uncovered.

3. Cover and let it sit overnight, without using.

4. The next day, open the tub and check FC only. (It should be >10ppm).

5. Let the jets run (with air) for 20 mins, cover and let sit overnight again, without using.

6. Continue steps 4 and 5 until your FC is around 3 ppm. (may take a few days)

7. Check CC.

Your tub will be clean as a whistle at this point. Meaning your CD should be at its baseline (whatever that is), and CC should be well under 1.0. If not, you may be getting false readings.

I appreciate this. It does go one step further in explaining how to do a more effective shock.

I also appreciate the advice to refill. The tubs getting a bit irritating now even though it's only got 2 months use.

Thanks so much for your replies...

[Fungi]

What year is your J345? If it is not a 2009, your fill volume is not what you say it is. In 2009, Jacuzzi changed the shell configuration and added another 100 or so gallons. My 2005 J345 fill volume is 336 gallons. Check your owner's manual, and with Jacuzzi if needed. This could be screwing up your chemical load.

Haaa!!! That explains a lot. I thought I remembered the fill volume being more like 350. But approaching 50 I decided to check on the internet to check the accuracy of my memory. It said 450... So assumed I remembered it wrong. lol Thanks for the reality check! I think mine is the 07 bought it as their 50th anniversary model. Thanks again!

I'm not going crazy! lol

[shovelhd]

What year is your J345? If it is not a 2009, your fill volume is not what you say it is. In 2009, Jacuzzi changed the shell configuration and added another 100 or so gallons. My 2005 J345 fill volume is 336 gallons. Check your owner's manual, and with Jacuzzi if needed. This could be screwing up your chemical load.

Haaa!!! That explains a lot. I thought I remembered the fill volume being more like 350. But approaching 50 I decided to check on the internet to check the accuracy of my memory. It said 450... So assumed I remembered it wrong. lol Thanks for the reality check! I think mine is the 07 bought it as their 50th anniversary model. Thanks again!

I'm not going crazy! lol

If yours is a 2007, then it has the same fill volume as mine, 336 gallons. Methinks this is the root of all of your chemical problems.

[Fungi]

If yours is a 2007, then it has the same fill volume as mine, 336 gallons. Methinks this is the root of all of your chemical problems.

Nah, my biggest problem is I found this forum too late. I had already used sanichlor for too long before I learned here to stop at around 20-30, then switch to bleach. I don't really use the tubs capacity to calculate anything. I only mentioned it here cause I didn't know if it was valuable information for troubleshooting purposes. Thanks again, Jim

[Nitro]

What year is your J345? If it is not a 2009, your fill volume is not what you say it is. In 2009, Jacuzzi changed the shell configuration and added another 100 or so gallons. My 2005 J345 fill volume is 336 gallons. Check your owner's manual, and with Jacuzzi if needed. This could be screwing up your chemical load.

Haaa!!! That explains a lot. I thought I remembered the fill volume being more like 350. But approaching 50 I decided to check on the internet to check the accuracy of my memory. It said 450... So assumed I remembered it wrong. lol Thanks for the reality check! I think mine is the 07 bought it as their 50th anniversary model. Thanks again!

I'm not going crazy! lol

If yours is a 2007, then it has the same fill volume as mine, 336 gallons. Methinks this is the root of all of your chemical problems.

If his tub is 336 Gallons, but he's adding enough Chlorine for 450, that doesn't explain the sanitation issues. If anything there would be less issues.

[Nitro]

I measure the tub before we get in and it's around 3ppm. The average chlorine used by us when we soak is around 1ppm. For me adding 1/2 cup raises chlorine 7ppm, My math says 3 - 1 +7 = 9. The tub uses 6 overnight so we're back to 3 the next night. So it's using from 5 to 6 ppm. If I add more wouldn't the values just go up.

Ok this is just as simple, sorry for using the incorrect term. So the tub uses between 5 and 6 repeatably I was using this as the chlorine demand. I have tried to hit 8 as the target for chlorine when I add after a soak. I guess using your percentage method, 3/9=.33, 1-.33=.67 or 67%

Re-read my link on Chorine Demand. You need to measure your IDLE Chlorine Demand. That means you need to shock to 10 ppm, let sit overnight (WITHOUT using it), then check FC the next day.

IDLE CD is represented as a Percentage and will stay the same regardless of your FC level. What you are measuring is how much FC is needed while soaking. Nice to know, but is not the same as CD.

[Fungi]

I measure the tub before we get in and it's around 3ppm. The average chlorine used by us when we soak is around 1ppm. For me adding 1/2 cup raises chlorine 7ppm, My math says 3 - 1 +7 = 9. The tub uses 6 overnight so we're back to 3 the next night. So it's using from 5 to 6 ppm. If I add more wouldn't the values just go up.

Ok this is just as simple, sorry for using the incorrect term. So the tub uses between 5 and 6 repeatably I was using this as the chlorine demand. I have tried to hit 8 as the target for chlorine when I add after a soak. I guess using your percentage method, 3/9=.33, 1-.33=.67 or 67%

Re-read my link on Chorine Demand. You need to measure your IDLE Chlorine Demand. That means you need to shock to 10 ppm, let sit overnight (WITHOUT using it), then check FC the next day.

IDLE CD is represented as a Percentage and will stay the same regardless of your FC level. What you are measuring is how much FC is needed while soaking. Nice to know, but is not the same as CD.

There's no magic about using 10ppm except it makes for easier math. Perhaps my explanation is a little confusing. The bottom line is I add chlorine after use using math in my head... BUT I test it before closing the lid for the night. So I adjust chlorine for a target of 8-9ppm after we are done with it for the night. The following night I test it before we get in. So for example If I add chlorine to a level of 9ppm after use, and it's 3 the following night before use, those numbers should work in the math just as good as adjusting to 10.

3/9=.33, 1-.33=.67 or 67%

My testing for chlorine needed for a soak has been from 1-1.5ppm pretty reliably. Thanks, Jim

[Nitro]

There's no magic about using 10ppm except it makes for easier math. Perhaps my explanation is a little confusing. The bottom line is I add chlorine after use using math in my head... BUT I test it before closing the lid for the night. So I adjust chlorine for a target of 8-9ppm after we are done with it for the night. The following night I test it before we get in. So for example If I add chlorine to a level of 9ppm after use, and it's 3 the following night before use, those numbers should work in the math just as good as adjusting to 10.

3/9=.33, 1-.33=.67 or 67%

My testing for chlorine needed for a soak has been from 1-1.5ppm pretty reliably. Thanks, Jim

Sorry, yes you are correct. I missed your percentage calculation.

If your CD is 67% (with no Ozonator), you're not using enough Chlorine, which would explain the high CC. You should try to get CD down under 50%.