Finally there!

[bbrock]

After a major partial drain/refill, then a ridiculous amount of MA additions and aeration to lower the TA, I am now where I want to be (or at least good enough):
FC 8
CC 0
pH 7.2
TA 70
CYA 50
CH 800

Now that I got these levels dialed in, will the weekly addition of water due to evaporation change things? If so, what will it change?

Through the forum, I am expecting the pH to rise with time as that sounds as though more common than it falling. Also, with my CH 800 and my TA 70, I can keep balanced water based on 75° temp by keeping a pH from 7.1 to 7.6. At this point, should I bother continuing to aerate to try to get to 7.5?

Also, in the event of pH drop, do I add borax per Pool Calculator, which shows it will slightly increase TA (but less than soda ash/washing soda) or do I aerate?

Thanks for all the help in getting my pool to this point!

 

[zea3]

Don't worry about the TA. Adjusting TA is only important if your pH is rapidly rising or falling and you have difficulty maintaining a stable pH reading.Since your CH is way high at 800ppm, try and keep the pH between 7.0-7.5, don't let it get any higher. Keeping the pH low will help prevent calcium scale. You are at a greater risk of scale formation due to the high CH. Aeration raises pH so do not aerate unless it drops below 7.0, which is unlikely at this point. Do you have hard water in your area, or have you used a lot of cal-hypo for your chlorine source in the past? If you have hard water then your CH will continue to rise over time. CH does not evaporate out, it can only be removed by draining and refilling with a lower CH water source.

 

[Richard320]

You will probably never have to add Borax. I never do. Just topping off to replace evaporation drives the pH back up, as well as the TA. Your CH will continue to climb, possibly as much as 25 per week. Mine does.

 

[bbrock]

Wait... what? My CH and TA may rise by that much?

I have worked hard to get the #s where they are. Yes, I we have hard water where I am at (I tested the fill water 1x and if I recall correctly it was 300 or so). Zea3, I lowered my TA per the Pool School instructions that the level would have lead to imbalanced water that could have lead to scaling/plaster corrosion. While I understand not to adj. it if you can't maintain a stable pH, the reason I lowered it was very real as the plaster in my pool is probably on its last legs so I want to try to preserve it for as long as possible by maintaining balanced water. Don't want to spring for a resurface right now or in the near future if possible.

Speaking about CH rise, its strange Richard320 that you say it "could climb by 25" as the CH in my spa actually seemed to have fallen to 150 when I tested that recently. Maybe the pool and spa water/CH acts differently. A rise of 25 per week would be a pain.

 

[Richard320]

Wait... what? My CH and TA may rise by that much?

I have worked hard to get the #s where they are. Yes, I we have hard water where I am at (I tested the fill water 1x and if I recall correctly it was 300 or so). Zea3, I lowered my TA per the Pool School instructions that the level would have lead to imbalanced water that could have lead to scaling/plaster corrosion. While I understand not to adj. it if you can't maintain a stable pH, the reason I lowered it was very real as the plaster in my pool is probably on its last legs so I want to try to preserve it for as long as possible by maintaining balanced water. Don't want to spring for a resurface right now or in the near future if possible.

Speaking about CH rise, its strange Richard320 that you say it "could climb by 25" as the CH in my spa actually seemed to have fallen to 150 when I tested that recently. Maybe the pool and spa water/CH acts differently. A rise of 25 per week would be a pain.

The CH in your spa could not have dropped to 150 if the fill water is 300. Not unless you replaced water with water that's been run through a softener or rainwater. Go plug numbers into poolmath and see what happens to CIS when when the temperature gets up to 100 or so and the pH is up at 7.8. Oops - you've got scaling. That Calcium is still in the spa - it's just stuck to the walls instead of being dissolved in solution. A little bit is great - it adds traction. When it starts causing road rash when you brush your knee against the wall, you got trouble.

The TA is easy enough to beat back with acid. I do it constantly. Typically the TA in my pool is around 70 and when I add water it goes up a little, but when I adjust pH, it goes back down to 70. The CH will climb with evaporation. Yours may not climb 25 a week, but it will climb. And replacing water sometimes doesn't even get noticeable results. If I drain off 4" in my pool and use it on the lawn, I've replaced about 6%. My numbers are similar to yours. .94*800 + .06*300 = 770. One drop on the test. And the next week, or the week after that, it's back to 800 from evaporation.

 

[bbrock]

Will have to recheck CH in spa and fill water. This time I will record them.

Just so happens that I have been in the midst of trying to determine if my spa heater or pump was the cause of my breaker continuing to trip. I found it is the spa pump that has failed and is causing the trip. Wonder if it's related to an extended period of unbalanced spa water (or at least not finely managed) by the former home owner? The spa is an AG plastic shell, so while I can't get "corrosion to plaster," I can get "scaling." As such, wouldn't it be better to keep the pH more on the acidic side vs. alkaline?

 

[bbrock]

Back from weekend trip. Prior to leaving for two & a half days, I had brought the chlorine level up near shock level. I maintain a CYA of 50, so my normal chlorine range is 4-8, with a shock level of 20, but I raised it to 17 thinking that based on the amount of days I would be gone, the expected temperatures, & the usual burn off that I would be fine at 17. Well, things look okay. Here are my levels:
pH 7.6, FC 11, CC 0, TA 80, CH 725 (or 750), CYA 50

Prior to leaving I estimated my CH at 800, but I think it must've been wrong. That is one test I'm having trouble with identifying when the blue color sets in since it is such a light blue. Also, before I left TA was 70. After having recently done a partial drain & fill, I was trying to maintain a TA of 70 and had based things on a CH of 800.

I'm just not sure how I should approach things now. Think I read that a high chlorine level will raise the pH, but will it also raise the TA? Should I add acid to bring the TA down to 70? Not sure if that should be my goal since it looks now like the CH could be different from the 800 I had previously determined. Also, how do I handle the high FC of 11? Just wait for it to drop between 4 to 8 then start adding my daily amount? Before I had left I had gotten comfortable with doing the OTO daily and adding my usual amount of chlorine daily which was 12 oz. I would then test with the FAS-DPD 1x per week.

Any help would be appreciated.

 

[Richard320]

For the CH test, I use 5 drops of the R-0011L even though the directions say only 3.

And if you're not using a speedstir, there's part of the problem. Your wrist wears out too soon. My Ch levels dropped 200 when I switched from manual swirling to speedstir, with no other changes!

The high FC will be gone tomorrow. It's amazing it stayed as high as it did.

When you get your next pH reading after FC dips below 10, then add acid to drop it to 7.2. TA will go down with pH.

 

[bbrock]

Tx Richard. Really, why is it shocking the FC stayed up? Because it's been so hot? I estimated that by raising high it would be ok with the burn off.

Sounds like a speedstir could help. Just being cheap because I don't want to have to spend up to $30 to get one. Last few times I've been doing the FAS – DPD test in order to see when FC drops; can't use the OTO for this.

 

[Richard320]

Tx Richard. Really, why is it shocking the FC stayed up? Because it's been so hot? I estimated that by raising high it would be ok with the burn off.

Sounds like a speedstir could help. Just being cheap because I don't want to have to spend up to $30 to get one. Last few times I've been doing the FAS – DPD test in order to see when FC drops; can't use the OTO for this.

FC loss is a percentage, not a fixed amount per day. So if you double the FC reading, you lose it to sunlight twice as fast. Hence the need to add daily and not just put a week's worth in at once.

Order FAS-DPD refills when you get the speedstir. Might as well add some R-0012, too. You'll go through it a lot faster than most people.

 

[bbrock]

Got levels this AM:
pH 7.6, FC 9, TA 80, CH 700. I used 5 drops of R-0011L, which seemed to help with distinguishing the blue. I'm thinking the CH is probably somewhere from 700-800 with the varied results I have gotten lately. Water temp is approx 80, at least at surface. Should I still wait for my FC to drop between 4-8 before I add MA to bring down the pH and TA? And, if I was adding 12 oz./day chlorine before my vacation, how do I know now how much to add daily until next week's FAS-DPD test? 12 oz had been based on my pool losing 0.5 ppm chlorine from 8.0 to 7.5, but air temps were cooler last week, plus it was windy.

 

[SunnyOptimism]

After a major partial drain/refill, then a ridiculous amount of MA additions and aeration to lower the TA, I am now where I want to be (or at least good enough):
FC 8
CC 0
pH 7.2
TA 70
CYA 50
CH 800

Now that I got these levels dialed in, will the weekly addition of water due to evaporation change things? If so, what will it change?

Through the forum, I am expecting the pH to rise with time as that sounds as though more common than it falling. Also, with my CH 800 and my TA 70, I can keep balanced water based on 75° temp by keeping a pH from 7.1 to 7.6. At this point, should I bother continuing to aerate to try to get to 7.5?

Also, in the event of pH drop, do I add borax per Pool Calculator, which shows it will slightly increase TA (but less than soda ash/washing soda) or do I aerate?

Thanks for all the help in getting my pool to this point!

Man oh man, I'm still doing the drain and refill dance due to over-stabilized water. Been at it almost two weeks now. I'm hoping today is my last 2k gallon blow off and then I'll rebalance salt and TA. I'll check to see if I need to do a SLAM (need to do an OCLT to see if I'm losing FC to critters).

I'm tired and I can't wait to get my life back and actually let the family swim in the pool



Sent from my iPhone using Tapatalk

 

[Richard320]

Is there some reason you can't use the FAS-DPD test every day?

If FC is 9, then the pH test is valid. You can go ahead and calculate your acid dose and add it.

 

[bbrock]

SunnyOptimism, yes it is a pain in the butt, but once you get it done, it is very rewarding.

Richard320, I was trying to save costs with not using the FAS-DPD test. The reagents cost more, plus the OTO maybe good enough to daily check if there is chlorine. If I check daily with the OTO, then once a week with the FAS-DPD test, and add a daily amount based on my results with the FAS – DPD test, I think that may be be good enough/could work. Got that idea here from Jason Lion, as it seems like a good way to do things. Why would I want to test with FAS – DPD daily?

 

[Richard320]

SunnyOptimism, yes it is a pain in the butt, but once you get it done, it is very rewarding.

Richard320, I was trying to save costs with not using the FAS-DPD test. The reagents cost more, plus the OTO maybe good enough to daily check if there is chlorine. If I check daily with the OTO, then once a week with the FAS-DPD test, and add a daily amount based on my results with the FAS – DPD test, I think that may be be good enough/could work. Got that idea here from Jason Lion, as it seems like a good way to do things. Why would I want to test with FAS – DPD daily?

Because a few posts above you sounded rather doubtful about your ability to test things with the OTO. How can you add a daily amount based on a weekly FAS-DPD test?

A fifteen dollar FAS-DPD refill is pretty cheap insurance. Once you KNOW your pool's appetite, you can cut back a little on the exact testing. I personally, can't see any difference in the OTO test whether the FAS-DPD test tells me FC is at 4 or at 7. And that's a pretty good spread.

Anyway, you've got your plan all figured out, so there's nothing further to say.

 

[bbrock]

Richard320, I sincerely thank you for all your help. I'm not trying to sound like I know it all, because by means I do not. Simply, that I had formulated a plan based on what I had read in another post from Jason Lion and a system that sounds like it could work.

The way I add a daily amount is that whatever my 1x/wk FAS-DPD test shows I need to add to bring it to 8, I base that addition as my needed daily amount. By all means, I struggle with the OTO, but I am using it more so to verify that chlorine is present and it is above my minimum of 4. I am comfortable enough with the OTO test to know when I am above five with a darker yellow. If the yellow is continues getting lighter and I think it's at four before the next week FAS-DPD test, I know that my daily amounts have not been enough.

 

[bbrock]

For instance, I will retest tomorrow a.m. with the FAS – DPD test. Tomorrow will be the start of my week and the subsequent Wednesday will be my FAS-DPD test day. Whatever amount I have to add tomorrow to bring the level up to 8 will be the amount I add daily until the subsequent Wednesday when I retest. This will actually be the first whole week that I implement this method, but I hope/expect it to work.