Water Balance Nightmare - Causing Me To Drink Heavily

[DriveMeNuts]

I am a newbie to this site. I found this forum after searching for answers to my water balance problem. I have been working with my Pool Stealer-ship to no avail. The only thing positive from my partnership with the pool store is their profits. Wow, I actually feel better now...on second thought.... Okay, here goes.

We have a 20' x 40' (35,000 gallon) plaster (Grey bottom) pool with an auto safety cover. Oh yeah, the pool is four years old. Two weeks ago I pulled the cover back to check the status of the water. I noticed (no lie) thousands of fishing worms on the bottom. The pool water smelled like rot and was very cloudy. I decided I better open the pool and get them out of there. After removing the worms and decaying vegetation, I double shocked the pool (six 1lb bags of Calc Hipo 53% shock). The pool water said is that all you got. Actually it was...I did not have anymore shock. I tested the free chlorine level with my handy liquid tester (only tests Ch and Ph) and the level was 0. I took a sample to my pool store and the levels were.

April 27

FC 0.0

TC 0.1

PH 7.6

Hardness 300

Alk - 189

CA - 5

The pool store told me to add 6 3" tablets to the skimmer, add 1/4 gallon of Muriatic Acid, 8lbs of stabilizer, and triple shock the pool. Of course they were nice enough to sell me the chemicals right there (w/ a smile). I added the chemicals, tested the water about 30 minutes later and registered 0.5 ppm of FC. I took the sample to the pool store the next day. The readings were:

May 1

FC 0.4

TC 1.6

PH 7.3

Hardness 200

Alk - 188

CA - 40

They told me to add another 1/2 gallon of muriatic acid and calcium. I added no shock. The readings following this chemical add were.

May 3

FC 0.0

TC 0.6

PH 7.0

Hardness 290

Alk - 180

Phosphates 300

CA - 40

They tested for Phosphates this time. I was told to add another 1/2 gallon of muriatic acid and PhosAway (it should be called wallet away). They also told me to shock the pool. Instead of using the bags of shock. I decided to use Walmart 12% ultra bleach. I purchased 12 gallons. After adding 6 gallons initially, my FC was at 1.5 ppm. I kept adding bleach hoping my FC would get to at least 10 ppm. I added the remaining six gallons and the FC made it to 3 ppm. By morning it was down to 0. The readings after this round were.

May 8

FC 0.0

TC 0.1

PH 6.7

Hardness 270

Alk - 140

CA - 45 (increased due to adding bleach (i assume).

Today 5/8, they told me to add yet another 1/2 gallon of muriatic acid and a concentrated algaecide. I forgot to mention that I have 10 (ten) 3" tablets (Trichlor) in my skimmers.

I am at a loss as to what to do. I am tired of the trial-and-error my pool store is putting me through. Its good for them and I think I am helping keep them in business during the recession.

I have two main issues:

1) My Alkalinity won't drop. Now my PH is on the very low side. Could the unstable chlorine issue be causing the alkalinity to be resistant to change?

2) Why won't the pool accept chlorine? I read on another forum that I should add 2lbs of shock per 5,000 gallons of water to get the FC over 10 ppm. This would equate to 14 bags for me. I have only added a max of seven (thus far). I have 15 bags, but did not want to add them (for nothing).

I would greatly appreciate any thoughts, consultation, or recommendation on how to correct this problem. I also accept sympathy.....

Thanks a million.....

[chem geek]

1) My Alkalinity won't drop. Now my PH is on the very low side. Could the unstable chlorine issue be causing the alkalinity to be resistant to change?

2) Why won't the pool accept chlorine? I read on another forum that I should add 2lbs of shock per 5,000 gallons of water to get the FC over 10 ppm. This would equate to 14 bags for me. I have only added a max of seven (thus far). I have 15 bags, but did not want to add them (for nothing).

I'm sorry you are having problems. Take a deep breath, relax, and all will be well.

Your Total Alkalinity (TA) IS dropping, along with the pH when you've been adding acid. However, now your pH is low so what you need to do is aerate the water to raise the pH with no change in TA. When the pH rises to 7.2 or higher, you can add more acid to lower both the pH and TA. See this post for a table describing the procedure.

As for chlorine, it sounds like the Cyanuric Acid (CYA) you had in the pool upon closing has been converted to ammonia by soil bacteria that got into the pool. This creates a rather large chlorine demand. You can do a bucket test to see how much chlorine it will take before it will start to hold. Use chlorinating liquid or 6% unscented bleach (Clorox Regular or off-brand Ultra) so that you don't raise either the Cyanuric Acid (CYA) nor Calcium Hardness (CH) and just keep adding 10 ppm FC worth at a time every hour until it starts to measure. If you have a good test kit, you can measure the Combined Chlorine (CC) level and with an ammonia test kit from a pet/aquarium/fish store you can measure ammonia as well. The minimum amount of cumulative FC that it will take before it registers is found by using the formula (using raw measurements) of 8 * Ammonia - CC assuming the ammonia reading is in ppm Nitrogen (which is typical).

Richard

[DriveMeNuts]

Thank you for the advice. I just purchaed a test strip kit for ammonia. I conducted the test and the results came back at .25 ppm. Would this be enough to cause my chlorine problem? I calculate the amount of FC needed (based on the reults of the test and the formula you provided) -- (8 * .25) (ammonia) - 0.1 (CC) = 1.9 FC. Is this correct? That seems low considering I added 12 gallons of bleach to the pool. Unless of course I was ever so close to destroying all the chloramines and just did not have enough to sustain the FC levels.

If this is correct, how do I detemrien how much shock I need to add to the pool (35k gallon). I have 15 1lb bags. I wish I would have paid more attention in chemistry class.....

Thanks again for all the help.

[chem geek]

You may be pretty close to being done, but you can always do a bucket test to see how much chlorine demand there is left. 1/8th of a teaspoon of 6% bleach in 1 gallons is close to 10 ppm FC so that should give you some idea.

What kind of shock is in your 15 pound bags? Is it Cal-Hypo, Dichlor or Trichlor powder? Your Calcium Hardness (CH) is already high enough so you don't want to use Cal-Hypo and your Cyanuric Acid (CYA) is also OK so you don't want to add Dichlor or Trichlor. The following are chemical rules independent of concentration and pool size.

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.

For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.

For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by 7 ppm.

Richard

[DriveMeNuts]

Okay, here's where I am. I have four gallons of pool water in the bucket. I am up to 3tsp of 6% bleach. At present, I get a reading of about 20 ppm. I hope it holds.... I did the same test yesterday with 2 tsp of bleach. I woke up this-morning with a 0 FC reading.

Note: The pool store had me add 20 lbs of shock (Calc-Hypo) on Sat. On Sun I had 0 FC in the pool. The readings from the pool store water test post shock were as follows:

FC 0

TC 1.2

PH 6.7

Alk - 94

Hardness 220

CYA - 50

Here's the strange part. I am not getting an ammonia reading on the test kit I purchased. I thought the kit might be bad so I purchased another (first one from Wal-mart). Same results...no reading.

Any further gudiance or help would be appreciated.

Jack

[chem geek]

Jack,

That's truly strange because a Total Chlorine reading of 1.2 ppm with a Free Chlorine (FC) of 0.0 implies a Combined Chlorine (CC) of 1.2 ppm and that should register on an ammonia test as about 0.2 ppm, though maybe that's too low for you to see on the test. Ammonia tests really measure both ammonia and monochloramine combined.

Anyway, see if you get a chlorine reading in your bucket tomorrow (be sure to keep it away from direct sunlight -- you can also cover the bucket if you like). Hopefully it will hold and that will tell you that you are getting close. 3 teaspoons of 6% bleach in 4 gallons would normally register 60 ppm so clearly there's still something in your water reacting with chlorine. If you end up registering 20 ppm tomorrow morning, then that would be 40 + (60-20) = 80 ppm FC cumulatively needed to clear the pool. That would be a lot.

25 pounds of 65% Cal-Hypo in 35,000 gallons would be 55 ppm and would raise the Calcium Hardness (CH) by 39 ppm. Let us know what happens in the bucket tomorrow.

Richard

[DriveMeNuts]

Here's where I am now...I had a chlorine reading in the bucket test 48 hours after adding 3tsp of bleach to the bucket. The reading was 5 ppm. I added 34 gallons of bleach to the pool. In 48 hours, I was down to 1 ppm. I did another bucket test. I added 1/2 tsp and that held at over 5 ppm for 48 hours. I added 6 gallons of bleach and then another 6 gallons the following day. Its been over 48 hours and my chlorine levels are holding above 10 ppm. I think maybe I am finally there. I had the water tested today and here are the results:

FC >10 ppm

TC >10 ppm

CC 0

PH - 6.8

Hardness - 260 ppm

Alk - 120 ppm

CA - 10 ppm

Question - My CA was 55 on May 10 (date of last test). Since the last pool company test I added 48 gallons of bleach (over the course of a week). I am trying to figure out why my CA dropped significantly. I noticed my Alk increased between the tests. Could there be a correlation between the two? I plan to add some CA to the pool this-evening.

Final question, how do I know if I am out of the woods on the Chlorine issue? It will be 72 hours at 8:00 pm tonight.

Richard...you have been awesome.....

Thanks....

Jack

[chem geek]

Your Cyanuric Acid (CYA) probably dropped significantly because the pool was "let go" over the winter without maintaining chlorine, so bacteria were able to grow. There are quite a few types of bacteria (and some fungi as well) that can use Cyanuric Acid as "food" and when they do so, the metabolize it into ammonia and other intermediate products that require a lot of chlorine to get rid of. The technical explanation for this is described in this post.

[DriveMeNuts]

I appologize for the delay in responding regarding the status. After adding the 48 gallons of bleach....the CC went to 0 and has been holding chlorine levels. My FC and TC levels are currenlty at 3 and have been this was for the past two weeks.

Thanks so much for all the advice. Richard, You Are Da Man....

[chem geek]

I appologize for the delay in responding regarding the status. After adding the 48 gallons of bleach....the CC went to 0 and has been holding chlorine levels. My FC and TC levels are currenlty at 3 and have been this was for the past two weeks.

Thanks so much for all the advice. Richard, You Are Da Man....

Congratulations. It does sound like you had the bacteria conversion of CYA to ammonia. It certainly gives one more reason to maintain chlorine levels at all times if possible.

[Pool-newb]

Unless you want to get rid of your CYA.

In that case, allow the cl level to fall to zero, go dig up a shovel-full of dirt from the nearest swamp or even your garden, scatter that dirt around the pool edge with the pump running on recirculate, then keep testing the CYA level. Once it's down to the level you want (possibly several days?), start shocking the heck out of the pool.

Chem Geek - I don't know what you do during your day job but it seems like this could be a marketable item - get together with a microbiologist and isolate a set of the bacteria that eat CYA, then sell them as a treatment (replacing the dirt in the procedure above). Best outcome would be if you could package it in small envelopes like bread yeast, but even if you had to sell it in buckets of dirt I can imagine you'd have customers.

[chem geek]

Well, it's not very controllable, especially having the bacteria grow and not algae. Also, in the worst-case for every 10 ppm CYA that gets converted to 3 ppm ammonia it takes at least 24 ppm FC to clear it. It does not happen reliably nor in most pools (most pools just get algae when the FC gets too low). Unfortunately, other than water dilution and this uncontrolled bacterial conversion, there's not another way to lower CYA though there is a melamine-based product that will precipitate it, but turns the water cloudy and takes forever to filter (just like the CYA test).

[Pool-newb]

Hey, I just came up with the idea, you get to put the bell on the cat.

The reason I even thought about this was that when it happened to me it happened very quickly - probably over a day or two, and while I believe I did get algae at the same time, I don't think it was a really serious infestation.

My theory was based on keeping the pool well covered while this is going on, and having a very strong bacteria - and maybe even a of these bacteria.

And while I did use a lot of bleach getting back to clean, I can still imagine it a viable solution at least in some situations, for example:

- Where water is scarce and/or expensive

- For really large pools to save water, or really small pools where things would move fast anyway

- Where the pool can be kept tightly covered while without chlorine and does not have much problem with blowing in leaves or other vegetation.

When I was having my CYA problem I could not find the melamine based product anywhere, or, if so, I seem to remember that it would have cost more than refilling the pool.

So what about using sulphuric acid as a floculant and then vacuuming it out? Would the sulphuric acid cause too many other problems?

[imnay]

May be a mistake to post into this thread but, frankly, most of the alchemy suggested here has me completely at a loss.

We've had our 27ft. round AGP with expanded depth and extra water outlets to filter and returns to the pool for over 20 years and we have never, never had to use any of the chemical additives or techniques posted here. Even the few winter seasons we just quit filtering or adding chemicals from like Jan. to end of March we have NEVER encounted the problems and specially the corrective suggestions posted.

We always use simple 4-way test kits and add either soda bicarb or soda ash when PH needs increasing or Alkalinity needs increasing - with PH and total Alkalinity in good range we just simple shock with liquid chlorine and regularly add algaecide while keeping our preferred sanitizer (chlorine tabs via in-line chlorinator) at normal level and we NEVER have a problem keeping our 20k plus gallons crystal clear and perfectly healthful.

Adding like 1/2 gallon of acid at a time? We always thought that max acid to add at one time NEVER more than a couple of cups so we never add more than two cups of acid at a time on the rare occasions PH or Alkalinity sometimes creep up to a too high level and we have never had a problem.

Maybe we are just too stupid to know better - our base approach is a pool will either have a "sour stomach" and needs bicarb of soda or a "sweet stomach" and needs soda ash or on rare occasions when levels are too high then a LITTLE bit of acid.

I read posts from people that sound like dark ages alchemists and - LOL - gotta ask where is all this coming from - cause and again after over 20 years of easy success with pool water management and with neither of us being genius brains we say from our experience that pool chemistry just ain't ever rocket science.

Get PH good and get Alkalinity good and do a thorough shock and then with adequate filtration system, regular algaecide use and constant good level of sanitizer of choice and your water should be clear and clean and always ready for swimmers. Problems should be easily corrected in days.

So often it seems like something really simple is made really difficult - no offense intended - keeping a home pinball game in good operation is like 1000 times harder than treating pool water.

Best Wishes to All but with most of the complicated solutions suggested for correcting pool water problems at our house we just don't get it.

[chem geek]

... regularly add algaecide while keeping our preferred sanitizer (chlorine tabs via in-line chlorinator) at normal level and we NEVER have a problem keeping our 20k plus gallons crystal clear and perfectly healthful.

This is the main reason why you don't have any problems. Yes, pool maintenance can be incredibly simple. I only use $15 worth of 12.5% chlorinating liquid in my 16,000 gallon pool per month and a small amount of acid every month or two and that's it.

However, most people don't maintain their pools as diligently. They also don't all use an algaecide (or phosphate remover) so when they do let their chlorine level drop too low or let the CYA get high from continued use of stabilized chlorine products, they then run into trouble. Also, some people HAVE to close their pools due to winter freezing so they can't keep chlorine in the pool at all times -- so if they don't keep chlorine in the pool until the water gets very cold and they don't open early in the spring before the water warms up, then they can run into problems.

Just curious -- do you have a filter such as sand that you backwash regularly? Do you have rain that overflows the pool or otherwise dilute the water? Just wondering how high your Cyanuric Acid (CYA) level may be at this time. With the algaecide, that will prevent algae growth in spite of a high CYA level.

[kg4kmd]

I am a newbie to this site. I found this forum after searching for answers to my water balance problem. I have been working with my Pool Stealer-ship to no avail. The only thing positive from my partnership with the pool store is their profits. Wow, I actually feel better now...on second thought.... Okay, here goes.

We have a 20' x 40' (35,000 gallon) plaster (Grey bottom) pool with an auto safety cover. Oh yeah, the pool is four years old. Two weeks ago I pulled the cover back to check the status of the water. I noticed (no lie) thousands of fishing worms on the bottom. The pool water smelled like rot and was very cloudy. I decided I better open the pool and get them out of there. After removing the worms and decaying vegetation, I double shocked the pool (six 1lb bags of Calc Hipo 53% shock). The pool water said is that all you got. Actually it was...I did not have anymore shock. I tested the free chlorine level with my handy liquid tester (only tests Ch and Ph) and the level was 0. I took a sample to my pool store and the levels were.

April 27

FC 0.0

TC 0.1

PH 7.6

Hardness 300

Alk - 189

CA - 5

The pool store told me to add 6 3" tablets to the skimmer, add 1/4 gallon of Muriatic Acid, 8lbs of stabilizer, and triple shock the pool. Of course they were nice enough to sell me the chemicals right there (w/ a smile). I added the chemicals, tested the water about 30 minutes later and registered 0.5 ppm of FC. I took the sample to the pool store the next day. The readings were:

May 1

FC 0.4

TC 1.6

PH 7.3

Hardness 200

Alk - 188

CA - 40

They told me to add another 1/2 gallon of muriatic acid and calcium. I added no shock. The readings following this chemical add were.

May 3

FC 0.0

TC 0.6

PH 7.0

Hardness 290

Alk - 180

Phosphates 300

CA - 40

They tested for Phosphates this time. I was told to add another 1/2 gallon of muriatic acid and PhosAway (it should be called wallet away). They also told me to shock the pool. Instead of using the bags of shock. I decided to use Walmart 12% ultra bleach. I purchased 12 gallons. After adding 6 gallons initially, my FC was at 1.5 ppm. I kept adding bleach hoping my FC would get to at least 10 ppm. I added the remaining six gallons and the FC made it to 3 ppm. By morning it was down to 0. The readings after this round were.

May 8

FC 0.0

TC 0.1

PH 6.7

Hardness 270

Alk - 140

CA - 45 (increased due to adding bleach (i assume).

Today 5/8, they told me to add yet another 1/2 gallon of muriatic acid and a concentrated algaecide. I forgot to mention that I have 10 (ten) 3" tablets (Trichlor) in my skimmers.

I am at a loss as to what to do. I am tired of the trial-and-error my pool store is putting me through. Its good for them and I think I am helping keep them in business during the recession.

I have two main issues:

1) My Alkalinity won't drop. Now my PH is on the very low side. Could the unstable chlorine issue be causing the alkalinity to be resistant to change?

2) Why won't the pool accept chlorine? I read on another forum that I should add 2lbs of shock per 5,000 gallons of water to get the FC over 10 ppm. This would equate to 14 bags for me. I have only added a max of seven (thus far). I have 15 bags, but did not want to add them (for nothing).

I would greatly appreciate any thoughts, consultation, or recommendation on how to correct this problem. I also accept sympathy.....

Thanks a million.....

[kg4kmd]

I am a certified pool operator maintaining a pool for a special needs school. I add acid to lower my pH which is the exact results you are getting. My understanding is get the pH balanced first. The pH should be 7.2 - 7.6 with 7.4 desired. Here are some formulas:

To increase pH and change 0.2 (7.0 - 7.2) add 6 oz oer 10,000 gal so 3.5 times 6 =21 oz

To decrease pH and change 0.2 7.6-7.4) add 12 fld oz muratic acid per 10,000 gal

To increase Free Avail Chlorine with Triclor (granuals) for each 1 ppm per 10,000 gal add 1.5 oz

To increase Free Avail Chlorine with calcium Hypo for each 1ppm per 10,000 gal add 2 oz

Note the Chlorine granuals are not stablized and will burn off in daylight so when I shock I do it just prior to leaving work and have come back just before dark to do it.

I had to take a course to certify to operate the pool; sounds like with the investments you are making you might want to take one. Or atleast try to find materials with the formulas included. The distructions on the outside of most of the stuff has that. I put the formulas in a spread sheet for myself so I don't have to do the math every time. I can just look for my 30,00 gal pool and know that if pH is 7.0 i add 33 oz calcium hypo, etc.

For me the health department wants my pH 7.4 again with the slight veriance and Chlorine 6 - 10 ppm. I have to maintain a daily log of my levels and what I did, I recommend you do that for awhile.

If you have to add different chemicals wait an hour between I would wait atleast an hour before retesting.

I have a background in hazardous materials be very careful with the chlorine, it was the first modern chemical warfare agent and the evacuation distances from a chlorine gas tank are something to see. Lots of stuff will cause the chlorine in your pool products to liberate. Store NOTHING on top of them.

If you keep having problems try taking a sample to that company again and another company, compare results. I would tell the other company and not the one you are presently using and you might want to check with better bussiness the status of present company.

Oh other things I was taught If you smell chlorine at a pool it is because there is not enough chlorine in the water. Eyes sting due to pH. If its not a hot tub maintained by you don't even walk by it.

Keep brushing and vacuuming to make sure algae is gone as much as possible.

Hope this helps some.

[waterbear]

Maybe we are just too stupid to know better

I thinki that sums it up nicely!

[waterbear]

Maybe we are just too stupid to know better

I think that sums it up nicely!