Burning through chlorine

[Mikecn]

Had my pool for 3-4 years. Keep it open all year long. Live in Texas use to triple digit days. I have a 10,000 gallon pool. CYA is 50ppm I use 12.5% liquid chlorine with the whale on the label. I add chlorine as though I use 10% chlorine. All my reagents are less than a year old and I buy direct from Taylor. I have not seen rain just mid 90s-100s with direct sun (pretty much every year) I am having no issues with any other balance of my pool. I set my chlorine to 8ppm every night. Exactly 24 hours later I have 2ppm with 0ppm combined chlorine. So I’m adding a little over half a gallon of chlorine every day.

I don’t remember burning through so much in previous years. Is anyone else in a similar climate experiencing the same? Am I just remembering wrong?

 

[TinFoilHat]

That is an example of algae in the pool. Time to SLAM. Perform the Overnight FC Loss Test (OCLT) first to confirm this.

 

[Mikecn]

That is an example of algae in the pool. Time to SLAM. Perform the Overnight FC Loss Test (OCLT) first to confirm this.

Even with 0ppm combined chlorine? And keeping my pool open all year adding chlorine to max for my CYA every night?

 

[Mdragger88]

If you’re regularly letting fc drop below minimum (4ppm for you)
FC/CYA Levels
It is very possible that you have algae brewing.
Average daily loss this time of year in texas can be up to 5ppm - that’s without any swimmers.
Anything over 5 ppm is kinda suspect.
Btw- 8ppm is not max - it’s simply high target range.
Max is slam level which is 20ppm fc for you.
It is fine to dose a little higher than target range if that’s what it takes to keep you clear of minimum before your next dose.

 

[Mikecn]

Let me ask this final question. Everyone in my neighborhood seems to have a crepe myrtle. I use skimmer socks and pull a couple of handfuls of petals out daily in addition to what I physically skim from the surface of my pool. Never seem to get much debris in the bottom. Could the petals, as they are organic, be causing the drop?

 

[JJ_Tex]

Could the petals, as they are organic, be causing the drop?

Not really. I would do the OCLT, but suspect you have algae.

Note that 8 is the top of the target range, but many people go well above that to give themselves buffer and drift down into their target range through the day (just look at my avatar and you can see I'm way above my target of 5). Once you get this straightened out, make sure your focus is staying far away from the minimum and not just focusing on the top of the target.

 

[wireform]

Once your for sure in the clear up the CYA to the 70 range.

 

[Mikecn]

2 hours after adding 10 cups of 12.5% chlorine to a 2ppm 10,000 gallon pool I’m at 7.5ppm chlorine. I have my chlorine set at 10% in pool math so either my chlorine isn’t what it’s labeled as or I have a serious problem. I’ll check again when I leave for work at 4 am

 

[Mikecn]

just measured at 6.5ppm

 

[wireform]

You need to do
Overnight Chlorine Loss Test.

 

[Mikecn]

You need to do
Overnight Chlorine Loss Test.

That’s what I did

 

[Mikecn]

Since I only lost 1ppm of chlorine between 9:15pm (sunset is a little after 8:30pm here) and 4am that would indicate I passed the overnight chlorine test. I added chlorine after testing this morning. I retested before I left for work at 5:30. My ppm was where I expected so that rules out diluted/weak chlorine. So what else could it be since it seems I really only lose chlorine during daylight hours. And the general consensus is that I’m losing too much to be attributed to sunlight and evaporation.

 

[TinFoilHat]

The sun and the heat will eat it up so maybe it's just the way your pool has evolved. My pool characteristics change too sometimes.

 

[Mikecn]

Well this morning I left with it testing at 22ppm. I just tested and it’s at 5ppm

 

[Mikecn]

Definitely due to elements. It has been overcast here all day and the temperatures have been lower. I only lost 5ppm since adjusting it last night. It was suggested I set my CYA to 70 what is the general consensus on that? How will a SWG hold up to that kind of load. I am only a part owner and honestly didn’t want this pool I am also the only person taking care of it. I have been trying for a while to convince the other owners that we need to invest in a SWG. The big hang up is if we have to drain for any reason it all goes to greenbelt, also they don’t care for the skin feel of salt water pools.

 

[an1vrsy]

Mike, Get the Taylor K-1766 Salt drop test addition to your current kit. You may be surprised how high you chlorine pool has a salinity level. Each addition of the following adds salt, muriatic acid, liquid chlorine, sweat from swimmers, etc. You may already have a salt pool.

 

[Sunnydaze]

Definitely due to elements. It has been overcast here all day and the temperatures have been lower. I only lost 5ppm since adjusting it last night. It was suggested I set my CYA to 70 what is the general consensus on that? How will a SWG hold up to that kind of load. I am only a part owner and honestly didn’t want this pool I am also the only person taking care of it. I have been trying for a while to convince the other owners that we need to invest in a SWG. The big hang up is if we have to drain for any reason it all goes to greenbelt, also they don’t care for the skin feel of salt water pools.

It's not the sun/heat if you lost 17ppm of chlorine yesterday unless your CYA is very, very low. Or the testing is inconsistent. When something doesn't add up (and it's not) you'll want to find out what is causing the fluctuation.