Dialing it in...

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BMeeley

BMeeley

Bronze Supporter
Oct 13, 2017
106
Woodbridge, VA
Just an update on my newbie TFP method progress. After a partial drain and refill, receipt of my TF-100 test kit, cheap bleach, muriatic acid and supplies, I couldn't be happier. Despite being in Northern Virginia (first snow tonight), I keep the pool open and modestly heated late. Getting ready to close in the first 2 weeks of January (we like the hot tub on NYE!). Algae blooms are gone and the numbers are getting there.

Dec 4 test after partial drain/fill:

FC 1
CC 0.5
pH 7.8
TA 120
CYA 60
CH 200

Added 64 oz 20 Baume acid and 121 oz of 8.25% bleach. Let it sit for a few days and then tested again.

Dec 8 test

FC 0.5
CC 0.5
pH 7.5
TA 120
CYA 50 (real close to dead center between 50/60, but took my best guess without extrapolating)
CH 200

Will test again in a couple of days to see if things are leveling off now that I've solved the CYA problem (was well over 100 using pucks and strips).

Well on my way to my first SLAM before closing. Water temp maintained ~64 F with gas heater.

Any observations or thoughts for this home-titrating fool? :cool:
 
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Good point. Dropping pH and aerating, though I only have the spa to do that. Beat the CYA. TA is next, unless there's another priority. Getting a feel for the method and the pool before SLAM and close. Pretty cool, though, for a rookie! That reminds me... gotta go fire up the bubbles. Forgot to do that earlier.
 
Update: TA is coming down slowly and FC beginning to stabilize some. Today's readings:

FC 1.5
CC 1
pH 7.3
TA 110
CYA 60
CH 200

Added 28 oz Acid and 121 oz Bleach. Aerating through the spa for much of the afternoon. Keeping an eye on CSI, which is hovering on the low end at -0.53. If I'm not mistaken, that should come back toward 0 as TA comes down and pH drifts back up toward 7.5. I'm thinking I'd like to get TA closer to 90 before SLAMing. I don't really know why, but that feels like the thing to do since I'm not going to close for another 4-6 weeks, regardless.

Diggin' it. Much better than what I had going even 2 weeks back.
 
Just a few more thoughts on what you're doing:
1 - With those test numbers, I'm seeing -0.43 CSI. Not bad. Don't forget to ensure the water temp is updated when you use the calculator.
2 - Of the three (TA, CH, and pH), pH will move your CSI the most. You're preparing to close, so keep any changes fairly subtle. No need to move things too much. Your numbers are not too bad. As TA gets lower, CSI will also go down, so watch that too on the calculator. Woody has a point above about watching the TA because 120 was beginning to get up there, which can increase pH. But at the same time, don't feel like it needs to be at a specific number. They key with TA is finding a good number that keeps the pH steady. If you are doing the acid/aeration method to lower TA, maybe consider stopping at about 90-100 to see if the pH stays steady in that cooler water.
3 - Even though the water is cold right now, watch the low FC. Your elevated CC indicates some excessive product is in the water. It may not be a problem at the moment, but could make things more difficult when opening in the spring. So I'd increase the FC now to at least your recommended target range (based on the current CYA) and monitor it as well.

Hope that helps.
 
Very helpful. I've been adding Cl based on what Pool Math says for a target of 4 for FC. Water temp is now at 72, but I'll probably back that off to 65 or so later today.

You're right about the excessive product. Pucks and strips for 3 seasons had me all out of whack. I'm working on getting things back in range and getting a "feel" for my pool. Intentionally not trying to chase specific numbers. Looking more for signs of stability (especially pH and FC) by testing every few days. Getting TA closer to 90 (not precise) seemed to make sense. It had been as high as 180, if I can believe the old Clorox strips and app.

To give a better sense of background, here are ranges from the old app/strips/pucks and pool store additive regime (which was costing me a fortune):

October
Total hardness hovering around 500
Total chlorine between 1 and 3
Free chlorine at 0
pH swinging between 6.8 and 7.8
TA hovering around 180
Stabilizer up around 100
Chronic algae blooms and conflicting recommendations from the app every time I tested. A total mess.

Coming off that situation, I am THRILLED with my current numbers. Looking to steady pH and make a decent SLAM possible to close. With draining and then rain/snow/possible fill in the spring, my hope is that CYA will be around 40 for opening, with minor adjustments needed for TA and CH. Tweak and enjoy, right?

Both an art and a science, I'm learning. cheers
 
Missed the target FC for CYA of 60 is 8, so ran that through and added another jug of bleach to get closer to FC of 8. Still aerating to drive TA down around 90-ish. Will then see if pH stabilizes and focus on FC and CSI.

Feel free to chime in if you see something odd in my approach. But I'm having a blast and again am thrilled with where I am compared to weeks back.

TFP rocks! :rockon:
 
So, here are today's results. Still getting a feel for how quickly or slowly these things move, especially the acid/aeration process.

Water temp - 65 deg F
FC - 1
CC - 1
pH - 7.2
TA - 110
CYA - 50
CH - 200
CSI is showing -0.6

Added 242 oz bleach toward target FC of 8. Continuing aeration through the spa and brushed down the sides, cleaned out skimmers. Raising temp to 69 deg F to see if slightly warmer water will speed things up at all. Not in a rush, just developing a feel for small changes and what moves with what.

Not sure if raising CH to 260 will affect how some of the other pieces work together. May try that later or tomorrow if I can find the right CaCl. Prestone Driveway Heat seems to be straight CaCl without the sodium, magnesium, etc. Will have to see if any local stores have it.

Keeping the faith! :cool:
 
Raising the CH will increase your CH a little, but not a huge number to get back to neutral (zero). Letting the pH rise will do that faster. For example, if your pH were closer to 7.5, the CSI would be closer to about -0.22 which is a very good place to be. I know you've been working diligently on trying to bring the TA down, but you might find that leaving it alone and letting the pH rise a bit might just be a good place to stay for a week or two before you close to see how stable everything remains. If you do let the pH go back up to about 7.5 or so with the TA at about 100-110, and the pH grows like crazy in just a few days, then sure, try to bring the TA down a bit more to perhaps 80-90.

Also, not sure if you're doing it this way already, but folks here seem to have better success lowering the TA when they let the pH rise all the way up to about 7.8 "before" knocking it way down with acid again to about 7.2. It seems to have a more dramatic effect on the TA (lowering).

Finally, I think it's time to really watch that FC closely. Two gallons of 8.25% bleach should increase your FC by almost 6.5 FC points. Your water is still cool, even with a heater, so it shouldn't be losing more than 4 ppm per day which is why I'm also concerned about the elevated CC (over .5). You may want to start reading ahead about the SLAM process (link in my sig) so that you know what to expect at closing to rid the water of any algae or excess organics prior to closing. No surprises. :)
 

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Preparing for SLAM (been reading a lot) is exactly why I've been trying to get a handle on CYA, then TA. Agreed on letting things settle for a few days. I'm also concerned about the FC levels, but my bad experience to date has me partly convinced that CYA, then TA and possibly CH are keeping me in a place that maintaining a shock level of 20-24 is going to be tough. Though maybe what I'm seeing is actually the signal that it's time to SLAM. Was hoping to be able to use a little less bleach. 7.5 gallons seems like a lot and advice has said plan to have 4x that on hand when starting the SLAM.

Thanks for piling on. Much appreciated. It's a great process and I have tons of confidence in it. Will be starting with more manageable levels when I refill in the Spring. That's my story and I'm sticking to it. Muahaha.
 
Ha ha. It's a learning curve but it will settle and you'll get into a very nice routine soon. As for bleach for example, in the heat of S. TX summers, I add about 1/2 gal of bleach to my 17K pool each day. But this time of year, my water temp is at about 60 right now, and I barely add a gallon a week (if that) because everything slows down so much. I expect once you get it all under control, you'll see a much less amount of bleach required in the cooler water. Stay with it. You're handing the "piles" of info just fine. :)
 
Today's installment. One or two minor surprises, but still playing with all the pieces. I also need to read through Pool School or the Deep End to see if I can get a better understanding of how each level may or may not affect the others. I feel pretty solid on CYA and FC. CH and TA and such make basic sense. Part of my getting a feel for my pool is getting a feel for how these things play together... or not, as the case may be. That said, for those keeping score at home...

Water temp - 65 deg F
FC - 2
CC - 1
pH - 7.5
TA - 120
CYA - 50
CH - 175
CSI is showing -0.33

pH rise with overnight aeration, as expected. Mildly surprised that TA rose a bit (though could be testing error, not too proud to admit the occasional anomaly :cool:). Same with CH, though I did buy some CaCl (I like my plaster where it is).

Just to see if some more FC might hold better overnight, added 363 oz of bleach (which should target ~11 ppm vs normal 8-ish). I also added 10 lbs (~160 oz) of what they claim is 90% pure CaCl ice melt. That's about half what Pool Math called for, but I am intentionally making moderate changes. Solving everything all at once does not seem to be recommended.

We'll see where TA and CH go. Aeration stopped for the time being. Continuing to watch FC and mildly encouraged by a very slight upward trend.

cheers
 
I like to keep the concept of chemicals simple ....
- FC & CYA go together to keep the water clear, sanitized, and algae-free
- PH, TA, and CH go together to ensure the water is balanced for skin and the skin of the pool shell (scale versus erosion) - CSI.

A CSI of -0.33 is not too bad, and when the pH rises, it will get closer to zero. As for the TA jumping up slightly, usually I'd say that could be due to new water, but if no water was added it could simply be a testing anomaly. Regardless, if you decide to try and knock it down again, wait until the pH is clearly at 7.8 before hitting it with acid again. As we've already discussed, the water will need a SLAM as it's seems clear the FC is dropping too fast and your CC is elevated. But I wouldn't try to wrestle both scenarios. Do the SLAM when you are ready to pause on the pH/TA thing.

Enjoy! :cheers:
 
Preparing to SLAM this weekend. Pleased with the way the numbers are settling in, with the exception of course of FC. Thus the SLAM. Looking forward to opening the 2018 season early and with total confidence! :cool:

Yesterday's test results:

Water temp - 65 deg F
FC - 0.5
CC - 1
pH - 7.5
TA - 110
CYA - 50
CH - 275
CSI is showing -0.17

Time to load in about 24 gallons of bleach! Reading in the forum seems to recommend having ~4x the amount of bleach to reach shock level on hand is advisable. Thank God it's not that quantity of outrageous pool store or even pool supplier product. That would cost enough for me to consider moving! ;)

cheers
 
Wow, it is crazy how fast your FC has been dropping. By any chance, has anything else been added to the water other than typical acid or bleach? Any pool store items? Just wanted to make sure there's nothing else in that water that could account for the FC disappearance. If not, the SLAM is definitely in order. The key about the SLAM - "consistency". By that I mean once you add the initial amount of bleach to reach your SLAM FC goal (i.e. 20), you'll need to test FC frequently to ensure the pool is maintaining that SLAM level of 20 - add bleach as necessary to stay at 20. That's very important. At some point, the Bleach will stabilize and hold better over the days required to pass all 3 SLAM criteria (link below), but definitely check periodically throughout the day as best as your schedule permits to maintain the SLAM level. Also make sure you have an adequate amount of R-0870 (powder) and R-0871 (drops) for the testing. Use the 10 ML water sample size with one scoop of power and count drops until clear - divide by 2. Example: 40 drops = FC of 20. :)
 
Yep. Understood. And no, no pool store stuff since getting my test kit and doing the partial drain and refill. It was all pucks before then and CYA was way high. I needed that down to SLAMmable levels. Off to stock up on bleach and possibly start SLAM tomorrow. I get the gist but yeah, the algae blooms i was getting I'm sure have left plenty of organics behind. I figure the first few days will be adding plenty before it levels off.
 
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