2-year old IC60 not keeping Chlorine level up

[pjt]

I have been running the generator at 80% for 7 hours a day since late Spring.

That only generates 2.4 FC per day, which isn't enough for summer FC demand.

In early May, the pool was a bit cloudy and the Chlorine level was down to 1.2ppm.

That would indicate the need to SLAM. If you catch it early enough, it's quickly complete.

I just added 5# of baking soda to raise the TA.

That wasn't needed. TA down to 50 is fine.

CYA:75

Round up CYA readings to the nearest 10. Your CYA level is 80.

 

[dcsmith]

CYA Chlorine Relationship - Further Reading

www.troublefreepool.com

Synopsis: “a pool at SLAM level has only 1/5th the active chlorine (HOCl) as a pool that is within CDC guidance for safe and ideal.”
Slam level fc as per the chart will not damage surfaces, equipment, or swimmers.

Just so you’re understanding- your one time “shocks” may have kept algae at bay but likely didn’t eradicate it. Unless you did an
Overnight Chlorine Loss Test afterwards to prove this you can’t be sure.

About your ic60-
Here’s what 7 hrs/day @ 80% looks like in your pool
View attachment 517909
The average fc loss in an algae free residential pool can be around 5ppm/day in the peak of summer. Especially in Florida.
Around 2ppm in the spring. You must adjust your % & run time according to the season & conditions. It’s not set it & forget it.
Also, riding minimum is not recommended - it leaves no wiggle room for a high uv/high bather load day or whatever else occurs.
Going forward (after completing the slam process if necessary)
You want to maintain upper Target range fc so you know you’re covered.
View attachment 517910
FC/CYA Levels

If my algae is "at bay" since the first shock back in May, I would think my CC would be greater than .1, which it is today.

FC:5.7
CC:5.8
CYA:75

BTW: I do adjust both run time and SWG levels by increasing both during the Spring and reducing in late Fall. I monitor throughout the Winter as well.

As far as a high swim load is concerned, It's me and my wife several times a week in the Summer and perhaps a group of people ONCE during the Summer.

 

[dcsmith]

That only generates 2.4 FC per day, which isn't enough for summer FC demand.


That would indicate the need to SLAM. If you catch it early enough, it's quickly complete.


That wasn't needed. TA down to 50 is fine.


Round up CYA readings to the nearest 10. Your CYA level is 80.

This is what I have been using as my guideline. It says 70-80 for CYA. Also, TFP recommends no lower than 70ppm.

 

[reggiehammond]

An Overnight Chlorine Loss Test can confirm presence of algae. CC is not a good means as UV eliminates most CC during the day.

 

[JamesW]

If my algae is "at bay" since the first shock back in May, I would think my CC would be greater than .1, which it is today.

FC:5.7
CC:5.8
CYA:75

Algae and CC are mostly unrelated.

How are you getting these exact numbers?

 

[JamesW]

Why Do I Have Algae With a CC of 0?​

CCs are a sign that nitrogen based substances like ammonia or urea have reacted with chlorine and have formed "combined chlorine".

It then takes a certain amount of "free chlorine" to complete the oxidation process which ends basically with nitrogen gas being released.

CCs are common in pools with high bather load, they are usually more of a problem in public pools than in residential pools, especially when following the TFP protocol because there's always enough FC to quickly deal with the little CC that forms.

Maybe after a big pool party, especially with little kids involved that have to much FOMO to go to the bathroom.

Plants, such as algae, create chemicals like glucose from carbon dioxide and water. Using light, the carbon in carbon dioxide oxidizes the oxide into oxygen.

6CO₂ + 6H₂O --> C₆H₁₂O₆ + 6O₂

Carbon dioxide + water--> glucose + oxygen.

This is how plants make oxygen and store energy in sugars. Most of the bulk of plants is carbon from carbon dioxide. Most of the weight of a tree comes from the air.

The carbon in carbon dioxide is in the +4 state.

The carbon in glucose is 4 at 0, 1 at -1 and 1 at +1.

The carbon is "reduced", which is the opposite of oxidized.

Reduced just means that the oxidation state is lower or reduced because the atom gained electrons which are negatively charged.

When chlorine oxidizes the carbon in glucose back to a +4 oxidation state, it reverts back to carbon dioxide.

This is a similar process to an animal using oxygen to burn sugars to release energy and exhale carbon dioxide.

So, chlorine reacting with algae is mostly an oxidation reaction and not a combination. Algae is mostly converted back into carbon dioxide and water.

Chlorine can combine with carbon compounds, such as methane (CH₄) by replacing the hydrogen ions.

Carbon in methane is in the -4 oxidation state.

Algae mostly does not create CCs.

CCs are mostly created by compounds like ammonia where the nitrogen is in the -3 state.

For ammonia, you get combination and oxidation.

So, the CCs eventually go away, especially in sunlight where UV photons knock loose electrons from the nitrogen and make it easier for the chlorine to take them.

Active chlorine is +1, so it bonds with more negatively charged atoms, like nitrogen in the -3 state or carbon in the -4 state.

The carbon in algae has a zero net charge.

So, the reaction of chlorine with algae is mostly oxidation and not combination.



______________________________________________________________________________________________________________________


______________________________________________________________________________________________________________________

 

[dcsmith]

An Overnight Chlorine Loss Test can confirm presence of algae. CC is not a good means as UV eliminates most CC during the day.

Then what is the point of a CC test?

 

[JamesW]

Then what is the point of a CC test?

To detect CCs.

CCs are mostly nitrogen based compounds.

It is just one part of understanding the water quality.

A lack of CC does not mean that all is well.

 

[SecoSteve]

If my algae is "at bay" since the first shock back in May, I would think my CC would be greater than .1, which it is today.

FC:5.7
CC:5.8
CYA:75

BTW: I do adjust both run time and SWG levels by increasing both during the Spring and reducing in late Fall. I monitor throughout the Winter as well.

As far as a high swim load is concerned, It's me and my wife several times a week in the Summer and perhaps a group of people ONCE during the Summer.

This bold part above could be part of the problem. Letting pool water sit unused for long times will help algae get a foot hold. Ask me how I know that. I don't care if a pump is run 24/7, if nothing moves the water around, there are parts of the water that will be stagnant and, if near or below minimum algae could take over.

If you do not use the pool more often, then you should at least run a robot or vacuum a couple times a week.

 

[dcsmith]

To detect CCs.

CCs are mostly nitrogen based compounds.

It is just one part of understanding the water quality.

A lack of CC does not mean that all is well.

So other than performing the overnight Chlorine loss test, there is no way to tell if "all is well"?

 

[dcsmith]

Why Do I Have Algae With a CC of 0?​

CCs are a sign that nitrogen based substances like ammonia or urea have reacted with chlorine and have formed "combined chlorine".

It then takes a certain amount of "free chlorine" to complete the oxidation process which ends basically with nitrogen gas being released.

CCs are common in pools with high bather load, they are usually more of a problem in public pools than in residential pools, especially when following the TFP protocol because there's always enough FC to quickly deal with the little CC that forms.

Maybe after a big pool party, especially with little kids involved that have to much FOMO to go to the bathroom.

Plants, such as algae, create chemicals like glucose from carbon dioxide and water. Using light, the carbon in carbon dioxide oxidizes the oxide into oxygen.

6CO₂ + 6H₂O --> C₆H₁₂O₆ + 6O₂

Carbon dioxide + water--> glucose + oxygen.

This is how plants make oxygen and store energy in sugars. Most of the bulk of plants is carbon from carbon dioxide. Most of the weight of a tree comes from the air.

The carbon in carbon dioxide is in the +4 state.

The carbon in glucose is 4 at 0, 1 at -1 and 1 at +1.

The carbon is "reduced", which is the opposite of oxidized.

Reduced just means that the oxidation state is lower or reduced because the atom gained electrons which are negatively charged.

When chlorine oxidizes the carbon in glucose back to a +4 oxidation state, it reverts back to carbon dioxide.

This is a similar process to an animal using oxygen to burn sugars to release energy and exhale carbon dioxide.

So, chlorine reacting with algae is mostly an oxidation reaction and not a combination. Algae is mostly converted back into carbon dioxide and water.

Chlorine can combine with carbon compounds, such as methane (CH₄) by replacing the hydrogen ions.

Carbon in methane is in the -4 oxidation state.

Algae mostly does not create CCs.

CCs are mostly created by compounds like ammonia where the nitrogen is in the -3 state.

For ammonia, you get combination and oxidation.

So, the CCs eventually go away, especially in sunlight where UV photons knock loose electrons from the nitrogen and make it easier for the chlorine to take them.

Active chlorine is +1, so it bonds with more negatively charged atoms, like nitrogen in the -3 state or carbon in the -4 state.

The carbon in algae has a zero net charge.

So, the reaction of chlorine with algae is mostly oxidation and not combination.

View attachment 517948

______________________________________________________________________________________________________________________
View attachment 517950

______________________________________________________________________________________________________________________

View attachment 517949

Way over my head.

 

[JamesW]

I think that this is the main process of the chlorine reacting with the algae.

It does not form an intermediate compound like it can do with ammonia.

The reaction simply proceeds to completion.

C₆H₁₂O₆ + 6OCl^- + 6HOCl --> 6CO₂ + 12Cl^- + 6H₂O + 6H⁺

Glucose + Hypochlorite + Hypochlorous acid --> Carbon Dioxide + Chloride + Water + Hydrogen ions.

As you can see, when algae is fully oxidized, there is not much left.

You are basically reversing the process of photosynthesis.

Photosynthesis requires energy and oxidizing the glucose releases the energy back into the environment.

Chlorine oxidizes the nitrogen in ammonia to nitrogen gas, but it can form semistable intermediate compounds that show up as CCs.

Oxidizing ammonia creates acid by releasing hydrogen.

More than 95% of ammonia is in the form of the ammonium ion (NH4⁺)

2NH₄⁺ + 3OCl^- --> N₂ + 3H₂O + 2H⁺ +3Cl^-

When chlorine reacts with ammonia, the chlorine can substitute in for a hydrogen to form intermediate compounds like NH₂Cl (Monochloramine), NHCl₂ (Dichloramine) and NCl₃ (Trichloramine aka Nitrogen Trichloride).






Chlorine can react with a carbon compound like methane to form a semistable compound like trihalomethane because the carbon is in the -4 state.

CH₄ + 4CL₂ --> CCl₄ + 4H⁺ + 4CL^-

CH₄ + 3CL₂ --> CHCl₃ + 3H⁺ + 3CL^-

Trichloromethane is also known as chloroform and it can be a problem in heavily used indoor pools.

 

[JamesW]

So other than performing the overnight Chlorine loss test, there is no way to tell if "all is well"?

Basically, yes.

However, there are many different things you need do to determine if all is well or if all is not well.

You have to watch the clarity and if the water is not perfectly crystal clear, then you have issues.

If you do not pass the OCLT, then you have issues.

If you have CC levels above 1.0, you have issues etc.

 

[dcsmith]

Basically, yes.

However, there are many different things you need do to determine if all is well or if all is not well.

You have to watch the clarity and if the water is not perfectly crystal clear, then you have issues.

If you do not pass the OCLT, then you have issues.

If you have CC levels above 1.0, you have issues etc.

I will be doing the OCLT tonight.

Pentair just got back to me. They are saying that "if I SLAM my pool at a 28ppm level, I will damage the equipment.". This is what I am trying to understand! I am just a homeowner here. The so called Experts are not agreeing on this process.

 

[JamesW]

Sometimes, in life, this happens, and you have to figure it out for yourself.

We provide our opinions and other people provide their opinions and you have to figure out how to navigate the best course for you in the face of conflicting opinions and conflicting advice.

 

[dcsmith]

Sometimes, in life, this happens, and you have to figure it out for yourself.

We provide our opinions and other people provide their opinions and you have to figure out how to navigate the best course for you in the face of conflicting opinions and conflicting advice.

So you are saying the TFP Forum says the no damage to pool equipment, pumps, filters, lights, etc. will occur during the SLAM at 28ppm, yet the Pentair company says otherwise? If TFP is wrong, I may have a VERY expensive repair bill approaching.

 

[JamesW]

Super Chlorination burns out the swimmer waste that has combined with chlorine.

This frees the chlorine for sanitizing.

This is accomplished by raising the chlorine level quickly and dramatically.

When the chlorine level is raised to ten (10) times the amount of combined chlorine the pool water is said to have been super chlorinated.

As pool water is continuously passed through the IntelliChlor SCG while the unit is powered on, the water inside the IntelliChlor SCG is being super chlorinated.

Note: On initial start-up of a pool, it is best to super chlorinate using an outside source, i.e., use a shock treatment available at your local pool supplier.

https://www.pentair.com/content/dam/extranet/nam/product-related/product-manuals/pool-and-spa-equipment/intellichlor/IntelliChlor_Owners_Manual_Version_3_units_after_Nov_2011_English.pdf

Contact Pentair and ask them what it means to "Shock" a pool or to "Superchlorinate" a pool as they recommend.

 

[JamesW]

So you are saying the TFP Forum says the no damage to pool equipment, pumps, filters, lights, etc. will occur during the SLAM at 28ppm, yet the Pentair company says otherwise?

We are just giving you our opinion.

You are not paying us to provide you professional service.

Do whatever you feel comfortable doing, but do it at your own risk.

There is no warranty or guaranty that any advice is correct and/or safe.

No one is promising you anything.

The advice is what it is and it is presented “As-Is” and you can take it or leave it as you see fit.

 

[JamesW]

Call a professional to advise you and then you can hold them responsible for the results.

If you ask for free opinions on the internet, then you get whatever you get.

You make the final decision and you need to take responsibility for whatever happens because you are the person doing the work.

The person who goes hands on with the equipment has to take responsibility for whatever happens.

 

[Newdude]

So you are saying the TFP Forum says the no damage to pool equipment, pumps, filters, lights, etc. will occur during the SLAM at 28ppm, yet the Pentair company says otherwise? If TFP is wrong, I may have a VERY expensive repair bill approaching.

Thousands and thousands of pools have SLAMed for weeks with no issues. Some go a month or more. All documented here. Read and read and read until you believe it too.

The manufacturer will say what they say and then the pool store will have you 'shock' or even worse, 'super shock the pool blindly with no regard for what the FC level ends up, nor your CYA level to buffer it.

I had 8.5 seasons targeting 10 FC at my old house without issue. I have a little over 1 season at the new place doing the same. I've lost count how many times I've caught it at 15 or more.