Starting to take care of my pool.. wondering if partial drain and replacement is a smart idea to start

[mm3621]

Hi all,
first time I am posting here, I am a recent new member. Hopefully I inserted all required info in my signature.

So I am about to start taking care of my own pool in the next few weeks. Until now, the pool has been serviced by a pool maintenance guy for many years (I only bought the place in May of last year, but as far as I know he had been taking care of the pool for many years). I did my learning and studying on this amazing website as well as many other sources and I am wondering if, based on the test results below, it would make sense to start this journey with a partial drain and replacement to lower CYA and CH which, albeit still within the range, they are on the higher side of the acceptable range.

PS: I am well aware that FC needs to go up based on the CYA reading. This is how the pool guy has been keeping it.

FC: 3.5 ppm
pH: 7.8
TA: 80 ppm
CYA: 55 ppm (ideal range based on PoolMath is 40-55, with safe range going to 60)
CH: 475 ppm (ideal range based on PoolMath is 50-550)

In case it matters, my pool is plastered (replastered in 2014. There are quite a number of stains and other localized issues with the plaster).

 

[wireform]

You're looking good so far but need the CC test to complete the chemistry. How are you chlorinating ? Some pictures of the pool and equipment will help us help you further down the road.

 

[Jimrahbe]

mm,

I see no reason to drain any water from your pool... Your CYA should go down over time.. And 55 or 60 is not all that bad in a sunny area.

Thanks,

Jim R.

 

[mm3621]

You're looking good so far but need the CC test to complete the chemistry. How are you chlorinating ? Some pictures of the pool and equipment will help us help you further down the road.

Thank you! I did the CC test with the TF-1000Pro (my pool guy only tests pH and FC with the indicator block when he comes weekly) and it did not show any. I did it twice because I was not sure as it was my first time doing it, but it confirmed no CC. As for chlorinating, my pool guy has been using liquid chlorine. He comes weekly and he has been adding roughly 1/2 gallon of liquid chlorine each time he comes. From what I have seen, looks like the FC is around 1 ppm by the time he comes this time of the year, he adds 1/2 gal liquid chlorine and FC goes up to 3.5 ppm. When I take over (a few weeks from now) I plan to use liquid chlorine as well) and I plan to start by testing and adjusting daily.

 

[wireform]

We need testing to be all yours if it isn't. The comparator block is used mainly for the PH and the chlorine side is just to occasionally know if there's any doubt the water has chlorine. CC can only be tested with the fas-dpd test.

 

[mm3621]

We need testing to be all yours if it isn't. The comparator block is used mainly for the PH and the chlorine side is just to occasionally know if there's any doubt the water has chlorine. CC can only be tested with the fas-dpd test.

Yes, all the tests results I reported above are mine and done properly with the tf-100pro. I was just noting that the current pool chemistry is the results of someone else taking care of it based just on the comparator block tests as I have only seen him using that. But all the numbers in my original post are my test results, including no CC.

 

[Newdude]

Hey mm and Welcome !!!!

Until you take full control, you can still maintain an adequate FC per your CYA. (Round up, we call 51 to 59 a 60..... matter of fact, only pour it to the 10s and save yourself the trouble of splitting hairs).

The sun will burn off FC everyday, even on cloudy days. It's not so bad in Feb with a lower sun angle and shorter days, but it'll get hot by you real soon and you'll be losing 4 or more ppm per day. Weekly service just doesn't cut it.

Add liquid chlorine (pool essentials brand in the Walmart pool aisle is a fair price for 10%) so that you never sniff min FC. If you're losing 2ppm a day right now, and you're busy tomorrow, add 5ppm to cover you until your next test. (Etc etc). With 50 CYA, you never want to land at 5ppm or below for your next test. That's it. Its literally that simple. As the daily loss increases, you'll add more with it. Then it peaks and you'll add less and less each week through the fall.


It is safe to swim all the way up to slam which is 24 ppm for you. Use as much of that upper wiggle room as you need.

 

[mm3621]

Hey mm and Welcome !!!!

Until you take full control, you can still maintain an adequate FC per your CYA. (Round up, we call 51 to 59 a 60..... matter of fact, only pour it to the 10s and save yourself the trouble of splitting hairs).

The sun will burn off FC everyday, even on cloudy days. It's not so bad in Feb with a lower sun angle and shorter days, but it'll get hot by you real soon and you'll be losing 4 or more ppm per day. Weekly service just doesn't cut it.

Add liquid chlorine (pool essentials brand in the Walmart pool aisle is a fair price for 10%) so that you never sniff min FC. If you're losing 2ppm a day right now, and you're busy tomorrow, add 5ppm to cover you until your next test. (Etc etc). With 50 CYA, you never want to land at 5ppm or below for your next test. That's it. Its literally that simple. As the daily loss increases, you'll add more with it. Then it peaks and you'll add less and less each week through the fall.


It is safe to swim all the way up to slam which is 24 ppm for you. Use as much of that upper wiggle room as you need.

View attachment 629577

Thank you, that makes a lot of sense! Now that you say that, I think I saw him pouring two gallons of chlorine when I moved in last summer on his weekly visit, so that is probably how he was handling the larger loss of FC during the warmer days. I am actually surprised that with this low level of FC that has been kept through the whole winter I did not see any algae or other issues. Water is crystal clear. But yeah, I will go up to the target 7-9 ppm corresponding to 60 CYA and take it from there. Thank you!

 

[Newdude]

I think I saw him pouring two gallons of chlorine when I moved in last summer on his weekly visit, so that is probably how he was handling the larger loss of FC during the warmer days.

Go into the upper left menu of PoolMath and select effects of adding.



You were losing 25+ ppm a week and he was adding 11. Maybe he added some pucks to the skimmer for slow release FC, but he still fell short.

Anywho. 5+ ppm FC at all times is your mission. Hitting 5 doesn't garauntee algae but it's a chance. The more you do it, the more likely you are gifted a swamp.

will go up to the target 7-9 ppm corresponding to 60 CYA and take it from there.

Perfect. 4ppm may last a couple days right now, and it might last 5 hours mid day in July. Adapt as necessary.

 

[mm3621]

Go into the upper left menu of PoolMath and select effects of adding.

View attachment 629579

You were losing 25+ ppm a week and he was adding 11. Maybe he added some pucks to the skimmer for slow release FC, but he still fell short.

Anywho. 5+ ppm FC at all times is your mission. Hitting 5 doesn't garauntee algae but it's a chance. The more you do it, the more likely you are gifted a swamp.

Perfect. 4ppm may last a couple days right now, and it might last 5 hours mid day in July. Adapt as necessary.

Very interesting... I am 100% sure he was not using any puck, I would have seen it and I even asked him if he was. Is it possible I was not losing 25ppm per week? I live relatively near the coast, it usually not crazy hot in here.. anyhow, "somehow" the pool stayed clear and free of algae, how I am not entirely sure at this point! lol

 

[wireform]

Best would be for you to do a
Overnight Chlorine Loss Test and to be sure all is ok.

 

[mm3621]

Go into the upper left menu of PoolMath and select effects of adding.

View attachment 629579

You were losing 25+ ppm a week and he was adding 11. Maybe he added some pucks to the skimmer for slow release FC, but he still fell short.

Anywho. 5+ ppm FC at all times is your mission. Hitting 5 doesn't garauntee algae but it's a chance. The more you do it, the more likely you are gifted a swamp.

Perfect. 4ppm may last a couple days right now, and it might last 5 hours mid day in July. Adapt as necessary.

UPDATE: I added 1 gal of chlorine based on PoolMath calculations and I got FC to 6 ppm, perfectly in the 5-7ppm range recommended for CYA of 40ppm. Now, I also added some muriatic acid (1 qt) to lower the pH since it was reading 8.2. Somehow, it only went down to pH 8.0 and after adding another 1 qt of muriatic acid it basically stayed at 8.0 (basically at that red color that I can tell it is not 8.2 but it not 7.8 either, something in between). I also checked TA, it stayed at 80ppm. Question no. 1: Why is pH not going down? Is that because I added 1 gal of liquid chlorine which tends to raise pH? If so, question no. 2, should I just pour more muriatic acid until I get to pH between 7.6 and 7.8? Thanks for all your help!

 

[wireform]

Your PH showed 8.2 because it doesn't register higher but you may of had very high PH so add till you see movement and then use poolmath for the rest. Be sure which strength MA you are using as it'll have a different effect at lowering.

 

[sande005]

Liquid Cl may temporarily raise pH, but the effect doesn't last long. For all intents, it doesn't have any impact.
Your acid add at the very best would only drop pH by .3, so 8.2>7.9. Given the range of error of judging the colors, it did about what it should do. Add more acid if you want to drop it more. Another quart should do it. TA will slowly drop with acid adds, but both the impact of any one addition, as well as progress to a lower number, will take time. Give it a day or two before assuming it hasn't changed.

 

[wireform]

If you have good water circulation 1 hour is more then enough to see the results of the MA additions.

 

[Newdude]

+1 to readings high or low. They read as barely out of range and may be very out of range.

always raise/lower by 0.4 at a time, mix well for 15 mins, retest, repeat dose if necessary.

I read this 1000 times but it never clicked until we moved and inherited a tab pool with a bottomed out Ph. On dose 4 or 5, I got it. The 5point whatever Ph only *looked* like 6.8. Each dose got closer to reading on the scale but it took some tries.

 

[Newdude]

I added 1 gal of chlorine based on PoolMath calculations and I got FC to 6 ppm, perfectly in the 5-7ppm range recommended for CYA of 40ppm

This comment gets it's own response to hammer it home.

*you* are suggesting that with lower daily loss right now, that 6ppm will make it to the next test while remaining free and clear above min FC. The chart doesn't know the point in the season or your recent loss.

*you* will adjust your target regardless of what the chart says.

*you* will not blink if you have to go above 'target level' to achieve the mission.

And well done.

 

[wireform]

Nobody has brought this up so I will. You can benefit big time from a SWCG (salt water cell generator) pool which would be a game changer on your part.

 

[mm3621]

Nobody has brought this up so I will. You can benefit big time from a SWCG (salt water cell generator) pool which would be a game changer on your part.

Thanks, I am going to look into it.

 

[mm3621]

Best would be for you to do a
Overnight Chlorine Loss Test and to be sure all is ok.

Ok, one more update. I did the OCLT test and it seems everything is ok. I got a FC reading of 4.5ppm in the evening and 4.0ppm in the morning (I know I need to raise the FC to above 5.0 based on my CYA reading, this is only my 3rd day working on my pool and now that I understood daiuly losses and impact of chlorine addition I will bring it to the right range today). So I think I am good on that front. However, I am struggling to understand something else. Based on the last 3 days of testing, it appears I can conclude the following things:
- I lose about 1.5ppm of FC every 24 hrs (this seems to be consistent with values reported by others on this forum for the location and time of the year we are in).
- Approximately, 1 qt of liquid chlorine raises my FC by 1ppm. This is consistent with PoolMath app calculations.
- Approximately, 1 qt of MA lowers pH by 0.2 (also consistent with PoolMath)
With respect to chlorine, I guess I can simply pour 1.5 qt of liquid chlorine daily in the pool and I will maintain the FC within the range I am targeting. My issue boils down to pH. These are my pH readings in detail:
- 2/26 9:12am: pH=8.2, TA=80ppm
- 2/26 11:20am: Added 1 qt MA (I am using the 14.5% MA commonly sold at Lowe's or HD in CA)
- 2/26 11:35: pH=8.0
- 2/26 12:45pm: Added 1 qt MA
- 2/26 1:51pm: pH 8.0, TA=80ppm (basically seems my last addition of MA had no impact on pH and TA)
- 2/27 8:50am: pH 7.8. TA= Not Measured (ok, at least I see some reduction in pH. Maybe reading it at 1:51pm the previous day (just an hour after adding the MA) was too soon.
- 2/27 11:34am: pH=8.0
- 2/27 4:54pm: added 1.5 qt of MA
- 2/27 5:34pm: pH 8.0 (again, looks like no measurable impact on pH 1 hr after adding MA)
- 2/28 7:50am: pH 7.8, TA:70ppm (once again, seeing some reduction in pH and TA the following morning after adding MA

Do the numbers above make sense? Meaning, is it normal that lowering the pH with 14.5% MA is a bit of a struggle (meaning barely noticeable, lower by 0.2 at most with a quart of MA and then comes up again the following day)? All of this seems to be consistent with PoolMath, which also says pH should reduce by 0.2 with 1qt of MA. I guess my daily task will be to add 1.5 qt of liquid chlorine and 1qt of MA. However, here is the kicker: If all of this is true, how is it possible my pool was not green and full of algae when for a long time the pool guy was just coming once a week and adding 1qt to 2qt of muriatic acid and just 0.5 to 1gal of liquid chlorine during this time of the year? Looks to me his addition of liquid chloring would be barely sufficient for 3-4 days, with FC going to zero before his next visit. And pH should have also become an issue if he only pours 1 to 2 qt of MA. Am I missing something? and is it ok for me to keep adding MA every day to keep the pH between 7.6 and 7.8? Wouldn't that, at some point, bring the TA below the acceptable range?

Thank you!