Balancing dilemma with VERY hard source water

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glemerick

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Bronze Supporter
May 6, 2015
11
Columbus, IN
Hello,

I have two problems with regards to balancing my pool water & performing a regular chlorine shock routine. When I use chlorine shock, the pool water gets quite cloudy and I then have to floc it to clear it up (or deal with a very cloudy & unattractive pool for several days while the sand filter attempts to clean it). My calcium level is often found to be least 400 ppm (even the source water is 300-400ppm). I think it is the calcium precipitating out of solution which makes the water cloudy after shocking.

Here are my most recent numbers as tested by the pool store:
TC: 2.9
FC: 2.9
PH: 7.7
TA: 110
CH: 400
CYA: 110

I read it may also be the high CYA level I've got (110) that makes the pool cloudy after shocking with Chlorine.


Even if I drain & refill my pool to lower the CYA level, I will have the high calcium hardness level problem because my source tap water is very hard.


I have read that a solution to this problem (cloudy water after using Chlorine shock) is to use a chlorine-free shock. What do the experts here think about that? Any downsides to that, assuming I keep my Free Chlorine levels sufficiently high through my feeder tabs?


Here's what I'm thinking: If I want to avoid cloudy water after shocking, I need to avoid using liquid chlorine and use a chlorine-free shock instead. This means I need to keep my Chlorine levels high using my 3" tabs in the feeder.


This brings me back to the other dilemma. If I rely on my feeder tabs to maintain the chlorine level, this will eventually lead to an unacceptably high level of CYA.


How can I avoid a high CYA level? I could use liquid chlorine (without stabilizer) instead of the feeder tabs, but then I am certain that my calcium hardness problem will make the pool cloudy after putting in the liquid chlorine. I am feeling boxed in by this on two sides... Use liquid chlorine to avoid the high CYA problem but then that will result in a cloudy pool due to the high calcium hardness issue. Or I can rely on the chlorine feeder tabs (plus chlorine free shock) but then I will run into the high CYA problem.


In summary, I see two problems & only see a solution to 1 of them at a time, not a solution to both at the same time.
Problem1: High hardness resulting in a cloudy pool after chlorine shock. Proposed Solution: Avoid liquid chlorine, use chlorine-free shock and trichlor feeder tabs to maintain FC.
Problem2: Trichlor eeder tabs make CYA too high. Proposed Solution: Use liquid chlorine, but then I run into Problem 1 above, where my calcium hardness will result in a cloudy pool after pouring in liquid chlorine.


See the dilemma? Is there a way out? Thanks in advance for the help!

best regards,
Greg
 
Your CH is not high and is NOT the root cause problems of your pool problems. So the whole premise of your post is wrong.

We dont use shock or floc here. We dont use solid chlorine. We dont rely on pool store tests. We have sparkling trouble free pools.

Cloudy pools are caused by algea. You need to get your CYA down and Pool School - SLAM - Shock Level And Maintain
 
In eight years, the lowest my pool has seen CH is 440. At present, it's probably pushing close to 900. You know what? I can still tell that the screws holding the drain cover on are Phillips head. From the deck. Through eight feet of water.

I use liquid chlorine, about a quart of 12.5% per day during the season. It doesn't cloud things when I add it.

I use Muriatic Acid, about a quart a week, give or take.

I use a few trichlor pucks in a floater when I'll be gone more than three days.

That's it.

Never seen green water in my pool, either. Swimmable (aside from the temperature) 365 days a year for the past eight years or so. The secret is that I do my own testing and I've done it enough to really know my pool's chemistry intimately.

Chlorine-free "shock" interferes with the chlorine tests, and it does nothing to sanitize; it only oxidizes things. Dry forms of chlorine add unwanted Calcium or unwanted CYA or it's prohibitively expensive. (Lithium Hypochlorite) Which leaves Sodium Hypochlorite.

If you want a sparkling pool, get a real test kit and spend some time in Pool School. Start with ABCs of Pool Water Chemistry Move on to read about test kits and how to Chlorinate and Recommended Chemicals.
 
"In summary, I see two problems & only see a solution to 1 of them at a time, not a solution to both at the same time.
Problem1: High hardness resulting in a cloudy pool after chlorine shock. Proposed Solution: Avoid liquid chlorine, use chlorine-free shock and trichlor feeder tabs to maintain FC.
Problem2: Trichlor eeder tabs make CYA too high. Proposed Solution: Use liquid chlorine, but then I run into Problem 1 above, where my calcium hardness will result in a cloudy pool after pouring in liquid chlorine."

I see other problems... with a CYA level of 110, and a FC level of 2.9, I am ALMOST willing to bet that the cloudiness that you experience with added Chlorine is dead algae showing itself.
 
Thank you Richard, your reply is helpful.

I'll unpack a bit more why I thought it was hardness causing a problem with clouding whenever I added liquid chlorine. After a couple of shock, cloud, then floc cycles, the hardness actually came down from a peak of 700ppm to it's present 400ppm. From this I concluded that the floc was capturing the calcium and when I vacuumed it out and rechecked the hardness, the ppm had dropped significantly. Hence, I concluded it was the calcium coming out of solution that was causing the problem of cloudiness when I added the chlorine. I did not include that detail in the original post but that was the evidence I have which led me to conclude it was the hardness causing the cloudiness. However, I suppose correlation is not the same thin as root cause, but at least you can see my logic as to why I had evidence pointing to it might be the calcium.

It is quite useful to know that your hardness is in the same range as mine & you are able to dose it with liquid chlorine and experience no issues with cloudiness. With your data point now at hand, I must logically conclude that I have had something else coming out of solution as well and causing the cloudiness problem. I have read the ABC's & understand (now) the ideal ratio of FC to CYA documented in this forum. Since my CYA is high it could have been that coming out of solution I suppose or it could have been organic material caused by my imbalance of high CYA vs. too low FC.

I know from reading the pool school that I need to address my CYA vs. FC ratio. I think to do that I need to drain and refill the pool to get the CYA down. That will be my next task (in parallel with getting a better test kit).

Thanks,
Greg



Richard320 said:
In eight years, the lowest my pool has seen CH is 440. At present, it's probably pushing close to 900. You know what? I can still tell that the screws holding the drain cover on are Phillips head. From the deck. Through eight feet of water.

I use liquid chlorine, about a quart of 12.5% per day during the season. It doesn't cloud things when I add it.

I use Muriatic Acid, about a quart a week, give or take.

I use a few trichlor pucks in a floater when I'll be gone more than three days.

That's it.

Never seen green water in my pool, either. Swimmable (aside from the temperature) 365 days a year for the past eight years or so. The secret is that I do my own testing and I've done it enough to really know my pool's chemistry intimately.

Chlorine-free "shock" interferes with the chlorine tests, and it does nothing to sanitize; it only oxidizes things. Dry forms of chlorine add unwanted Calcium or unwanted CYA or it's prohibitively expensive. (Lithium Hypochlorite) Which leaves Sodium Hypochlorite.

If you want a sparkling pool, get a real test kit and spend some time in Pool School. Start with ABCs of Pool Water Chemistry Move on to read about test kits and how to Chlorinate and Recommended Chemicals.
Click to expand...

- - - Updated - - -

Thanks, I agree this is plausible given Richard's proof that high hardness doesn't necessarily cause cloudiness after shocking.
Greg


RonsPlc said:
"In summary, I see two problems & only see a solution to 1 of them at a time, not a solution to both at the same time.
Problem1: High hardness resulting in a cloudy pool after chlorine shock. Proposed Solution: Avoid liquid chlorine, use chlorine-free shock and trichlor feeder tabs to maintain FC.
Problem2: Trichlor eeder tabs make CYA too high. Proposed Solution: Use liquid chlorine, but then I run into Problem 1 above, where my calcium hardness will result in a cloudy pool after pouring in liquid chlorine."

I see other problems... with a CYA level of 110, and a FC level of 2.9, I am ALMOST willing to bet that the cloudiness that you experience with added Chlorine is dead algae showing itself.
Click to expand...
 
Welcome to the forum:wave:

Is there a way out?
Click to expand...
Yes. High CH fill water is problematic but there are some things to do to minimize it's effect....
1. Fill your pool with rainwater
2. Keep your pH lower....down around 7.2 - 7.5

You could be precipitating calcium but the two above things will help.....a lot.

Please read "The "ABC's of Pool Water Chemistry" up in Pool School. It'll reinforce some things you already know and clarify some things you didn't.

Be ready to ditch the pucks if you decide to manage your pool the TFP way. They can certainly be used as Richard320 does but he manages them correctly. BTW, how did you get a CYA test of 110.....is that pool store testing?
 
duraleigh said:
Welcome to the forum:wave:

Yes. High CH fill water is problematic but there are some things to do to minimize it's effect....
1. Fill your pool with rainwater
2. Keep your pH lower....down around 7.2 - 7.5

You could be precipitating calcium but the two above things will help.....a lot.

Please read "The "ABC's of Pool Water Chemistry" up in Pool School. It'll reinforce some things you already know and clarify some things you didn't.

Be ready to ditch the pucks if you decide to manage your pool the TFP way. They can certainly be used as Richard320 does but he manages them correctly. BTW, how did you get a CYA test of 110.....is that pool store testing?
Click to expand...

Thank you! Appreciate the advice on mitigating the effects of hard water. I have just gone through the ABC's and am working my way through several of the Pool School articles. Great stuff in there. The CYA reading of 110 was from the pool store. I have ordered the TF-100 kit & it should be here in a few days. I will post fresh readings with the proper kit asap.

I have always struggled with high CYA readings and can see how I need to get away from that using liquid chlorine but in the research I had done, I got worried that by using liquid chlorine I was going to run into cloudiness after dosing with the liquid chlorine due to my hardness levels (granted I think there are 3 or 4 other reasons for cloudiness & at this point I probably have all of them going on!). I am going through a series of partial drain & refill cycles to get the CYA level's down to the 30-50 range & generally get back to a healthier baseline water condition.

Thanks,
Greg

- - - Updated - - -

cfherrman said:
You you got your ch tests from the pool store it could be that they are off that much, yes that much
Click to expand...

True, but in the case of Indiana it's known to be a hard water state so I expect the real value of CH is high. Will post numbers from the TF-100 as soon as it arrives.
Thanks,
Greg
 
Do a set of tests on your pool water...
Then do a set on your tap/fill water (What you use to fill your pool).

That way you know what type of a baseline you have to work with.
 

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I did an experiment this evening to see if the hard tap water itself was sufficient to cause clouding when dosed with liquid chlorine. I simply filled a clear cup with tap water and then poured a small quantity of liquid chlorine (6%, Chlorox) in. There was no clouding. For reference, the water utility reports indicate a hardness of around 400 (depending on water plant location). I know my local tap may be somewhat different but this is the data point I have and will replace it with an accurate local measurement once the TF-100 arrives.


Would this suggest that something else is precipitating to cause the cloudiness? As RonsPlc hypothesized, could it be dead algae or other organic material that has not been oxidized due to the imbalance of FC/CYA?
 
OK got the TF-100 today. Here's what I've done the past few days while waiting for it to arrive...

Did 3 partial drain & refill cycles; I'd estimate I've got about 60% - 70% of the total water changed over. I then dosed the pool with 4 gallons of 12.5% Chlorine last night. No clouding! From this I conclude my hardness level was not causing the cloudiness previously, it was probably other dissolved stuff in the water (algae, organics, etc.) coming out of solution and precipitating. The pool has really cleared up at this point. Previously, I know my CYA was 3-4X what it is now and I was ignorant of the target FC level for such a high CYA level, so I now know I spent several weeks with an insufficient amount of FC and lots of junk building up.

This evening, I did the full range of tests with the TF-100. Here are my numbers:
FC 9
CC 3
CH 425
TA 260
CYA 30
PH 7.8

I've read the procedures in Pool School...
Since my CC is above 0.5, I believe I need to SLAM my pool, however looking at the prerequisites for SLAMing, my PH is high. I need to lower that before SLAMing.

Using Pool Math, I need to add 113 oz by volume of dry acid if I want to lower the PH to 7.2 (from it's current value of 7.8). I think this will also help lower my TA in combination with aeration.


So, next steps will be:
1.) lower the PH to 7.2
2.) SLAM

Anything else I'm missing? Thanks for the guidance.

Greg
 
glemerick said:
Using Pool Math, I need to add 113 oz by volume of dry acid if I want to lower the PH to 7.2 (from it's current value of 7.8). I think this will also help lower my TA in combination with aeration.
Click to expand...

Muriatic Acid is preferred to dry acid. Dry acid contain sulfates which just cause you water problems long term.

For a SLAM, lower your PH to 7.2 and then SLAM. Deal with lowering your TA later after your pool is clear.
 
ajw22 said:
Muriatic Acid is preferred to dry acid. Dry acid contain sulfates which just cause you water problems long term.

For a SLAM, lower your PH to 7.2 and then SLAM. Deal with lowering your TA later after your pool is clear.
Click to expand...



Ok, lowered the PH down to about 7.2 and did the SLAM, followed by the OCLT. The water is crystal clear now the past couple of days and I had only a 0.5ppm drop in FC during the overnight test!


Right now, my readings are
FC 4.5
CC 0
CYA 30

I've been able to demonstrate it wasn't the hardness originally causing the cloudiness upon dosing with liquid chlorine. Fresh water plus the SLAM cleared out the cloudiness, contaminants & got my CYA level down (by dumping lots of the old water to waste & replacing with fresh water). Driving down the contamination (which resulted from not having the right FC/CYA ratio for months / years) has given me water that doesn't get cloudy upon adding liquid chlorine which was my original struggle. It all makes sense now!

Best. Pool Forum. Ever.

Thank you,
Greg
 
glemerick said:
O
I've been able to demonstrate it wasn't the hardness originally causing the cloudiness upon dosing with liquid chlorine. Fresh water plus the SLAM cleared out the cloudiness, contaminants & got my CYA level down (by dumping lots of the old water to waste & replacing with fresh water). Driving down the contamination (which resulted from not having the right FC/CYA ratio for months / years) has given me water that doesn't get cloudy upon adding liquid chlorine which was my original struggle. It all makes sense now!

Best. Pool Forum. Ever.

Thank you,
Greg
Click to expand...

Greg, glad we could help. Now please stay around and support TFP and help explain your learning to others who wander here out of the pool store wilderness.
 
Way to work through the problem. Nice job.

I have CH350 fill water, and no CH rise. I connected my auto fill to my water softener. Solved.
 

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