More help with incessant pH rise

[mknauss]

Using trichlor you cannot maintain the FC/CYA ratio, especially if you only drain once a year. If you drain 1/3 to 1/2 of your pool volume each month, you have a chance. But to get proper FC levels based on the CYA level, using trichlor, you need it to dissolve at a very fast rate.

 

[nobody291]

keep from having to add murriatic acid for the rest of my life

My TA was 110 about 6 months ago when I installed my SWCG, and the pH would rise from 7.2 to 8 in about a week (and keep going up to the 8.2 max that the drop test will measure in the days that followed). I've slowly brought the TA down to 60 over that time, and my time between acid additions has gradually come up. This last cycle took about 3 weeks to go from 7.2 to 8 (pH rises from 7.2 to 7.6 over the first few days, then the rise from there is very gradual). So, I think you might benefit from doing something similar to reduce your TA. My fill water TA is 140, so I expect to need to continue to do this periodically to keep the pool water TA where it is now.

1 gallon Muriatic Acid per week, will cost me $850 per year in acid alone.

You pay $16/gallon of MA? Have you shopped around a bit more. Home Depot/Lowe's cost about $6 per gallon (sold as a 2 gallon pack) of 14.5% where I live in Cali.

 

[Bperry]

Okay, I'll try not knocking it down so much... but I'm starting to feel like I made a bad financial decision switching to SWG

Before:
$105/year on 50lbs of Trichlor (that's gone up recently to $400)
$150/year of city water to refill the pool to get rid of the CYA (which would often hit 100ppm in one year)

Now: (forecast)
Currently averaging in the cooler months: 1 gallon Muriatic Acid per week, will cost me $850 per year in acid alone.
(not counting the $1600 I spent on the SWG, the $120 on salt, the $90 Borate etc).

So... even with Chlorine being quadriple the price it used to be and the cost of replacing 20,000 gallons every year with "fresh" water... I would have been better off financially sticking to Trichlor... not to mention it was a very hands off method where I hardly had to do anything but keep the floaters full. My chemistry was almost always near perfect. Only needed to shock the pool once per year; free chlorine levels were easily controlled, and everything else stayed nicely in their correct ranges too--thanks of course to what this site has taught me btw... so I'll always be thankful to the knowledge and wisdom I've learned from this forum and the guides in general from TFP.

Acid demand will come down once your TA drops a bit and your plaster ages. It’ll also not require a gallon each week. Mine requires maybe a gallon/month at most in the summer time. Your pool is smaller than mine and so you will need even less acid.

One thing that’ll help is to use the 31.5% stuff as it requires less of it compared to the Home Depot stuff.

 

[skyeboysteve]

Using trichlor you cannot maintain the FC/CYA ratio, especially if you only drain once a year. If you drain 1/3 to 1/2 of your pool volume each month, you have a chance. But to get proper FC levels based on the CYA level, using trichlor, you need it to dissolve at a very fast rate.

Well, I was well aware of the increased amount of free chlorine needed as CYA climbed throughout the year... and reaching those goals with the trichlor I used was not a problem.

 

[skyeboysteve]

My TA was 110 about 6 months ago when I installed my SWCG, and the pH would rise from 7.2 to 8 in about a week (and keep going up to the 8.2 max that the drop test will measure in the days that followed). I've slowly brought the TA down to 60 over that time, and my time between acid additions has gradually come up. This last cycle took about 3 weeks to go from 7.2 to 8 (pH rises from 7.2 to 7.6 over the first few days, then the rise from there is very gradual). So, I think you might benefit from doing something similar to reduce your TA. My fill water TA is 140, so I expect to need to continue to do this periodically to keep the pool water TA where it is now.



You pay $16/gallon of MA? Have you shopped around a bit more. Home Depot/Lowe's cost about $6 per gallon (sold as a 2 gallon pack) of 14.5% where I live in Cali.

My bad... paying $16 per two 1 gallon bottles of 31.45% muriatic acid... so, actually my acid cost would be $425 per year.

 

[skyeboysteve]

Acid demand will come down once your TA drops a bit and your plaster ages. It’ll also not require a gallon each week. Mine requires maybe a gallon/month at most in the summer time. Your pool is smaller than mine and so you will need even less acid.

One thing that’ll help is to use the 31.5% stuff as it requires less of it compared to the Home Depot stuff.

Yes, I'm using the 31.45% stuff. I actually had my TA down to 20 at one point as I dumped in so much acid to try to get it down.... but it went up to 80 in a week's time--nothing added including no tap water.

 

[ferretbone]

" SWG hasn't run during this time... no water features, no swimming, no adding water from the hose.. only thing that breaks the surface is the polaris which loves to tie itself in knots more than usual lately."

Dude we have had three or four hard down pours in the last two months. And before you jump on to weather something.com for rain fall in inches, I keep open buckets in my truck, that I remember for sure were full or almost full of water. Once or more was overnight. I was caught in a freaking monsoon on 161 about Oct 24th. All that rain is your high PH.

And yes you already know new plaster is going to raise PH faster and higher than before for awhile. It will slow down, but for now use acid, or trichlor.

Just remember no one remembers what they had for lunch last tuesday, the monday before, or the month prior. Or better yet! Can you remember our last tornado watch in that storm that was going to rip through DFW? It was in Oct. Just saying. You might not be aware of how much new water has entered your pool. Plus you have new high PH plaster to add to your mystery.

 

[skyeboysteve]

" SWG hasn't run during this time... no water features, no swimming, no adding water from the hose.. only thing that breaks the surface is the polaris which loves to tie itself in knots more than usual lately."

Dude we have had three or four hard down pours in the last two months. And before you jump on to weather something.com for rain fall in inches, I keep open buckets in my truck, that I remember for sure were full or almost full of water. Once or more was overnight. I was caught in a freaking monsoon on 161 about Oct 24th. All that rain is your high PH.

And yes you already know new plaster is going to raise PH faster and higher than before for awhile. It will slow down, but for now use acid, or trichlor.

Just remember no one remembers what they had for lunch last tuesday, the monday before, or the month prior. Or better yet! Can you remember our last tornado watch in that storm that was going to rip through DFW? It was in Oct. Just saying. You might not be aware of how much new water has entered your pool. Plus you have new high PH plaster to add to your mystery.

True... I do keep a log of my test results and how much stuff I put in, but haven't been recording rain... granted I'm indoors so much I didn't even notice it rained till my wife mentioned it to me.

I guess part of the reason for why I feel so perplexed is combining past experience (when I was trying to only use bleach vs trichlor), and found myself losing control of my TA and pH as a result.... now that I've tried escaping Trichlor again, I'm faced with the same issue; and I guess perplexed that so many "minor" things like rain can effect my pool so much when it didn't seem to before with trichlor. Maintaining my pool and taking measurements twice a day has become quite the unexpected chore.

Maybe I'll just turn my SWG off until I use up the rest of my trichlor. Though someone told me once (or read somewhere) that the gel that dissolves off the trichlor tabs are bad for SWG... so not sure if that's true or not.

 

[Leebo]

Yes, I'm using the 31.45% stuff. I actually had my TA down to 20 at one point as I dumped in so much acid to try to get it down.... but it went up to 80 in a week's time--nothing added including no tap water.

So we’re using a quality test, awesome! Let’s go to the next item. Can you explain how you’re doing the tests? With a TA of 20 your pH will naturally swing rapidly as there’s nothing there to “hold it in place.” There’s something odd here I suspect.

 

[skyeboysteve]

So we’re using a quality test, awesome! Let’s go to the next item. Can you explain how you’re doing the tests? With a TA of 20 your pH will naturally swing rapidly as there’s nothing there to “hold it in place.” There’s something odd here I suspect.

Not sure what you mean by how I'm doing the test... carefully?

I keep reading that a lower TA usually buffers the pH from rising too quickly... so confused why too low makes pH more erratic... my pH never goes down on it's own--that's for sure.

 

[JoyfulNoise]

There is something not adding up here which points to either flawed testing, bad reagents, or chemicals not being correctly used. There is absolutely no way pool water can go from a TA of 20ppm to a TA of 80ppm in less than a week when the fill water, that is presumed to be the only source of alkalinity, is 70ppm. Even if you added 100 gallons per day of fill water to compensate for evaporation, then your TA would only rise by 2-3ppm in that time period.

So there is something very flawed with all the information being posted here.

Pool plaster should not affect TA once it is cured. Plaster is a mixture of calcium silicate and calcium hydroxide (and other stuff). When plaster cures (hardens), the surface layers absorb water to hydrate the silicates and carbonate ion to form calcium carbonate. After the surface carbonation is completed, which happens fairly quickly, the amount of calcium or carbonate ion emitted by the plaster should be relatively low. So, unless you are acid bathing your plaster and keeping it from undergoing carbonation, it is not a significant source of carbonate alkalinity. If you were acid bathing your plaster, you would see that as it would destroy the smooth surface and induce roughness.

So, again, something is not adding up here. Your pH is increasing from the normal outgassing of CO2 that occurs with water that has carbonate alkalinity in it. This happens in EVERY pool. You were not noticing it as much because the trichlor you were using was hiding that process. Liquid chlorine and SWG use has now revealed your pH rise. But, if you are seeing double digit increases in TA over short time scales (a week or so), that is from some kind of chemical addition. You simply cannot get that much alkalinity out of fill water unless you incorrectly tested the fill water and it's TA is much higher than 70ppm.

You need to investigate this more and test your reagents on know water samples to ensure that you are getting accurate results as none of what has been posted here is making any sense.

 

[skyeboysteve]

There is something not adding up here which points to either flawed testing, bad reagents, or chemicals not being correctly used. There is absolutely no way pool water can go from a TA of 20ppm to a TA of 80ppm in less than a week when the fill water, that is presumed to be the only source of alkalinity, is 70ppm. Even if you added 100 gallons per day of fill water to compensate for evaporation, then your TA would only rise by 2-3ppm in that time period.

So there is something very flawed with all the information being posted here.

Pool plaster should not affect TA once it is cured. Plaster is a mixture of calcium silicate and calcium hydroxide (and other stuff). When plaster cures (hardens), the surface layers absorb water to hydrate the silicates and carbonate ion to form calcium carbonate. After the surface carbonation is completed, which happens fairly quickly, the amount of calcium or carbonate ion emitted by the plaster should be relatively low. So, unless you are acid bathing your plaster and keeping it from undergoing carbonation, it is not a significant source of carbonate alkalinity. If you were acid bathing your plaster, you would see that as it would destroy the smooth surface and induce roughness.

So, again, something is not adding up here. Your pH is increasing from the normal outgassing of CO2 that occurs with water that has carbonate alkalinity in it. This happens in EVERY pool. You were not noticing it as much because the trichlor you were using was hiding that process. Liquid chlorine and SWG use has now revealed your pH rise. But, if you are seeing double digit increases in TA over short time scales (a week or so), that is from some kind of chemical addition. You simply cannot get that much alkalinity out of fill water unless you incorrectly tested the fill water and it's TA is much higher than 70ppm.

You need to investigate this more and test your reagents on know water samples to ensure that you are getting accurate results as none of what has been posted here is making any sense.

FWIW, the reagents I'm using are pretty new. Ordered them from this site a couple months ago. Is there a way to get known water samples? I've taken water samples to three different pool stores in my area, and got different TA results from each one from a sample taken the same day... so not sure what to trust anymore.

 

[mknauss]

Is there a way to get known water samples?

Standard Solutions

tftestkits.net

 

[Bperry]

Not sure what you mean by how I'm doing the test... carefully?

The suggestion was to describe the process for each test that you’re following or post a video of you doing it so they can look for testing errors. Maybe post a picture of the test tube results and how many drops it took to get that result.

 

[skyeboysteve]

The suggestion was to describe the process for each test that you’re following or post a video of you doing it so they can look for testing errors. Maybe post a picture of the test tube results and how many drops it took to get that result.

Here's a video demonstrating my testing the pH and TA levels:

 

[wireform]

Sky,
You have to keep the dropper bottle completely upside down and I watched the testing I observed you having it at an angle which creates issues with uneven droplets falling off the tip which leads to inaccurate results.

 

[Bperry]

Here's a video demonstrating my testing the pH and TA levels:

Yea, bottles need to be held vertically. I also don’t think you need to dry the tip of the bottle after every drop. I’ve heard people say it helps for cases where the drop size from the tip is “off” but I don’t know when that would be. Maybe you were just doing that for the demo but that would drive me crazy if I had to do that.

I’d give you an A. Probably A+ for video editing skills.

 

[Turbo1Ton]

As others have mentioned, you should have the reagent bottles fully inverted. You are wiping the tip of the R-0009 reagent between drops. Are you using a damp cloth? That is for reducing static buildup in the tip, as the R-0009 reagent drops can be affected by static. Total Alkalinity

The static could be affecting your tests when you are getting a large jump in TA, as the static causes the reagent drops to be smaller, therefore requiring more drops.

I think the wiping is generally only needed the first couple of times you use the reagent, but I do it every time as well.

--Jeff

 

[Leebo]

@JoyfulNoise …….I’d like your opinion on this as I’m not sure.

The TA test took about 90 seconds to add 7 drops of reagent 0009. It seemed to take a good amount of time. Could the test be “off” because of the length of time it took?

 

[skyeboysteve]

Sky,
You have to keep the dropper bottle completely upside down and I watched the testing I observed you having it at an angle which creates issues with uneven droplets falling off the tip which leads to inaccurate results.

Interesting... that's hard to believe, but now I want to experiment with the same sample of water and see how much variation there is. I do know that I CANNOT hold my R-0871 bottle vertical without the contents pouring out--this hasn't been an issue before. I suspect the size of the bottle (larger than ones I've had in the past) is contributing too much pressure on the nozzle from the mass of liquid in the bottle when held vertical.