Time to slam again?

[Envieddesigns]

Hey guys,
Yesterday I added some stabilizer to the water as well as 71 oz of liquid chlorine. Today I noticed the water a bit cloudy, FC at 2
pressure up on the filter about 3 psi. So I did a backwash, cleaned out the skimmers an filter basket and brushed the walls which was 2 weeks overdue. Added another 71oz of liquid chlorine. Should I do a SLAM?
Also looking back at my logs, the amount of liquid chlorine I was adding shouldve been a take sign that something was brewing? I feel the doses are not very consistent. From adding 35oz one day to 85 another.

 

[woodyp]

Cloudy water = SLAM time............just did mine for couple days, cleared right up.

 

[Envieddesigns]

Cloudy water = SLAM time............just did mine for couple days, cleared right up.

So last night during my second night of SLAM I ended up checking my CYA and it went from 40 to 50 so I dosed accordingly to get FC to 20 instead of previously 16. After 30 min I checked and FC went from 19 to 18.5 FC. I didn’t end up dosing again I went to bed woke up now to check FC still at 18.5. Should I continue to slam again to maintain the 20 FC?
Also I believe I’ve been doing my CYA test wrong the whole time I would only swivel the bottle to mix and never shook it?

 

[Katodude]

Is your water crystal clear? Until then keep SLAMing

Most people end up having to SLAM again, because they never really finished their first SLAM.

 

[Envieddesigns]

Is your water crystal clear? Until then keep SLAMing

Most people end up having to SLAM again, because they never really finished their first SLAM.

Yes. She started clearing up the day I started the slam after like 3-4 hours. I’m already two days in I might as well bring her up to 20 FCL based on current CYA an continue my slam you’re right.

 

[jark87]

And be sure to pass the OCLT before letting FC go below SLAM level. “Clear” water is subjective and can be deceiving.

Perform the Overnight FC Loss Test (OCLT)

The Overnight Chlorine Loss Test tells if the SLAM is finished or if you need to start a SLAM. This article says how to do the OCLT.

www.troublefreepool.com

 

[Katodude]

In the rare instances when I have to do a SLAM I always run the SLAM for at least one extra day after I pass all three criteria.

Then for at least a week I keep my FC at 20% of my CYA. Sort of a half SLAM. It makes sure everything is dead, dead, dead. Its much easier to maintain that level than a full SLAM.

Then and the most important part. Run you FC hot. The recommended level is now your new minimum level. Recommended is higher than that.

 

[jark87]

The recommended level is now your new minimum level. Recommended is higher than that.

I finally learned this a few years ago. Why does the SWCG chart show only minimum and a specific target, where the liquid chlorine chart shows minimum and a target range? I thought I was doing the right thing by hitting the target, when all along I should have been running hot. I probably could have avoided a minor algae outbreak if the chart was more clear on this subject.

 

[Katodude]

We are trying to teach thousands of users here and you need some sort of a chart. However, what you learn quickly is every pool is different. There are two things that I have observed here:

The hardest thing to do is get someone to buy a test kit.
After that happens the 2nd thing is getting people to run FC hot. Every newbie wants to run their FC as low as possible. People are scared of chlorine. Chlorine is a poison after all.

I have a SWG and my new minimum is 10% of CYA. As long as I test above that I am happy. Once I get close to that I dose the pool with LC.

 

[Oly]

What I realized is that your daily FC loss is the same whether you are at the minimum FC or running on the high side of your FC/CYA Levels Once you establish your FC base you save nothing by maintaining FC at the low end rather you expose your pool to low sanitation levels from high demand or sudden system failures. Now if your FC is significantly higher than your target FC your daily loss will increase but if a SWCG owner follows the FC/CYA Levels for a non salt pool there should be no issue. I always keep some 10% liquid on hand for high demand or sudden FC dips, like when my wife invites her girl friends over for aqua aerobics.

 

[jark87]

but if a SWCG owner follows the FC/CYA Chart for a non salt pool

I agree with the recommendations and follow the same logic of running higher FC than the target. But the above statement seems counter to an effective teaching method. Why have a SWCG chart if recommendations are to follow the liquid chlorine chart? And if there should be separate charts, why does 1 show a minimum and a target range while the other shows a minimum and a specific target number instead of a range? For years, I thought that I should be hitting the target - no more, no less, which is typically what is meant by the use of the word “target”. Instead, I was later told in threads like this one that the target is really the minimum. If true, the chart is very confusing at best, and wrong at worst.

This isn’t a complaint - I love TFP! I’m just trying help people avoid the same incorrect interpretation that I had.

 

[rich6429]

Then and the most important part. Run you FC hot. The recommended level is now your new minimum level. Recommended is higher than that.

What do you mean by 'Run your FC hot".

 

[Katodude]

Keep it above the recommended level. In a chlorine pool keep it slightly above the high end of the target. Keeps a buffer.

You will notice that all the mods and experts around here, run their FC hot. Guess who never have to do a SLAM.

 

[rich6429]

Keep it above the recommended level. In a chlorine pool keep it slightly above the high end of the target. Keeps a buffer.

You will notice that all the mods and experts around here, run their FC hot. Guess who never have to do a SLAM.

so having an FC of 6-7 is not harmful to your health or the equipment long term?

 

[Oly]

This isn’t a complaint - I love TFP! I’m just trying help people avoid the same incorrect interpretation that I had.

I understand and agree. I arrived at my sweet spot through experience with my system, location and usage. All pools are unique and require monitoring to recognize trends and anticipate issues. I also don't run my SWCG 24 hours a day. I view my pool sanitation like I did when I used liquid chlorine but now use chlorine gas. I moved my CYA up from 40 to 60ppm, run my SWCG 9 hours a day and use the FC target zone for a non salt pool.

 

[Katodude]

so having an FC of 6-7 is not harmful to your health or the equipment long term?

With your CYA of 60 much less harmful than 2ppm with 0 CYA.

 

[Orion7319]

I agree with the recommendations and follow the same logic of running higher FC than the target. But the above statement seems counter to an effective teaching method. Why have a SWCG chart if recommendations are to follow the liquid chlorine chart? And if there should be separate charts, why does 1 show a minimum and a target range while the other shows a minimum and a specific target number instead of a range? For years, I thought that I should be hitting the target - no more, no less, which is typically what is meant by the use of the word “target”. Instead, I was later told in threads like this one that the target is really the minimum. If true, the chart is very confusing at best, and wrong at worst.

This isn’t a complaint - I love TFP! I’m just trying help people avoid the same incorrect interpretation that I had.

This all had me really confused for the longest time as well. What’s really confusing is that for salt water pools, the app seems to list the minimum amount on the chart for salt water pools as the lowest number in the ideal range and lists the highest number from the chart for a chlorine pool as the highest number in the ideal range. For example the a salt water pool with a CYA of 60 shows minimum FC of 3 and the highest level of 9. Yet 10% of 60 is 6. So why is the minimum 3? What I do is try to maintain for 2 to 3 ppm over the 10% number and try to never let it fall below 10% of CYA.

 

[Orion7319]

so having an FC of 6-7 is not harmful to your health or the equipment long term?

The basic premise of the TFP method is to use FC in a specific ratio of the amount of CYA. Basically the CYA binds itself to a certain percentage of the FC in the pool and that FC basically does nothing but sit in reserve until it’s released by the CYA. The test kits can’t distinguish between the active and reserve amounts though. It’s my understanding, but I might be wrong that the CDC acknowledges this as well now, but they implement it kind of differently, by simply capping the number of CYA to 15.

The CDC's Limit for Cyanuric Acid in Swimming Pools

Cyanuric acid (CYA) protects chlorine from sunlight, but the CDC has set a CYA limit of 15 ppm for public swimming pools with a fecal incident.

blog.orendatech.com

 

[Envieddesigns]

So I just got home from work my issue is I’m gone from 9-6 so during the day I can’t keep up with the dosages. I dosed before leaving for work now I got home at FC was at 12. Just doses again to get her up to 20. Just boggles my mind the amount of chlorine I’m dumping in there. I’m assuming since I had been doing my cya test incorrectly maybe it was higher than what I was recording and required obviously more chlorine. Not sure. I didn’t have an issue last year. This is my second year doing TFP I thought ay last year was a breeze

 

[Oly]

TFP is a breeze, letting your pool water get sideways not so much.
What boggles the mind is how many living organisms it takes to make your pool water cloudy. Algae reproduces rapidly and requires chlorine to eradicate.
Once you are back on top test often for an early clue that you are not meeting daily FC demand. Keep your FC well in the target zone for your CYA FC/CYA Levels. Stock up on inexpensive CYA reagent and practice testing and add CYA in 10ppm increments to find and confirm your pools sweet spot. Every day check water clarity especially at night and run a quick Overnight Chlorine Loss Test if you have any doubt.
Getting your pool back into TFP shape takes some work keeping it there is much easier.