CR4 - The Engineer's Place for News and Discussion®

Previous in Forum: How internal lubricated silicones affect viscosity?   Next in Forum: Rarefaction of a Gas
Close

Comments Format:






Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







28 comments
Member

Join Date: May 2009
Posts: 9

Problems Raising pH to an Acceptable Level

05/18/2009 7:55 PM

The pool is in ground and 24,000 gals, approx. 25 years old, refilled from a well. The problem is we can not get the water balanced. In the past week, test 1 indicated the following (Free Available Chlorine 5) (Total Availabele Chlorine 5) (PH less than 7) (Total Alkalinity 0) Cyanuric Acid 100) (Copper/Iron 1) per our local pool chemical supplier, my wife has added ~64 oz of Metal Free, test indicated unwanted metals present. 24# Alkalinity Plus added to bring into acceptable level, which it did. Test 2 (PH ~7.0) (Total Alkalinity 80) (Calcium Hardness 300) (Phosphates 300) She was told to add 4# Soda Ash to raise PH and more if needed, over time. Also to add 8oz Ultra Bright Water Clarifier, which she did not do. She added 6# more with no increase in PH. Testing was conducted at home using chemical test kit and pool chemical supplier tests. On the 3rd visit to the supplier within the week she got frustrated with the salesman, because he started backtracking on what he had told her previously, that if she added as instructed the PH would come into accepatable range. She went to another supplier but didn't have any water left for him to test. Out of desperation she purchased PH Up and added 2# to pool retested in 4 hrs, no change in PH level. Added 2# more. This morning she tested pool water with little/no increase in PH level, still less than 6.8. The filteration system is a less than one year old Sta-Rite 500 sq. ft. dual cartridge filter with a 1 hp pump. The pool, right now, has a green tint. My wife just returned with the latest test results/what to do next, from the 2nd vendor (Total Alkalinity 130) (Cyanuric Acid 70) (Total Hardness 300) Total Chlorine 2.2) (Free Chlorine 1.8) (PH 6.2) Didn't buy any more chemicals. FYI: the pool can never be drained unless a relief valve is install because of a high water table. I NEED HELP. I am to the point of filling it in with dirt for a large vegetable garden. Thanks in advance

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
Hobbies - Automotive Performance - New Member Popular Science - Weaponology - New Member

Join Date: Oct 2008
Location: Want to be: 34° 34' 21.60" N, 92° 55' 42.28" W Really am in Arizona
Posts: 29357
Good Answers: 1098
#1

Re: PH can not be raised to acceptable level

05/18/2009 8:50 PM

Let's see, High water table feeds a well that supplies an in ground pool with water.

Water saturated with chemicals (groundwater) feeds your pool makeup source?

You might want to consider a pre-conditioner for your pool feedstock.

Florida?

__________________
Luck comes and goes. Skill is forever.
Register to Reply
5
Guru

Join Date: Jul 2006
Location: "Dancing over the abyss."
Posts: 4901
Good Answers: 240
#2

Re: PH can not be raised to acceptable level

05/18/2009 9:31 PM

You have several issues.

Your cyanuric acid above 75 indicates chlorine lock. Chlorine lock reduces effectiveness of chlorine in water and explains green tinge you describe.

If you can replace some of the water and switch to an unstabilized chlorine product (temporaily)you can solve this.

The high cyanuric acid also "biases " your total alkalinity reading; most calculations deduct 30% of the cyanuric acid reading from the TA value as the various cyanurates are weakly alkaline. Sso you started off with zero TA minus 30 equals minus 30 TA... your adjustment s to date got that above the 80-120 desired range so thats good for now.

Combined Chlorine: at 0.5ppm of combined chlorine, you need to superchlorinate or "shock" in order to destroy the chloramines that are the "combined chlorine." Total Available Chlorine minus Free Chlorine = Combined chlorine. You are right on the cusp (0.5Combined Chlorine indicates need to superchlorinate.)This may also explain some of cloudiness issues.(But I wouldn't do it until you have the doggone ph where it needs to be.) to superchlorinate you will have to get the chlorine concentration up in the 10-20 ppm range, which may be scary to you but after you have done this once, you will be OK with it. ( its a scary lot of shock, but then after the "crap" reaction products finish, all of a sudden you are right back where you should be...)

TA vs pH is more important than TA; But TA is important to help you hold pH.

Before I do any adjustments, I make sure that I get my pH stable, which is what you are trying to do. Since you have such a soup, I'm not sure what I would do but since your last TA was 130, Lets just try to get the pH right. I'd try to add 4-5 pounds of soda ash to get that ph from 6.2 your last reading to around to 7.0. (based on 20000 gallons, you've got 24000, but this gives margin of error) then you can add smaller amounts to fine tune it.

Finally how long do you run the pump?

Electricity is cheaper than chemicals, and circulating does many things (all good) for water chemistry.

Patience is a virtue, and solving one problem at a time is the best process in my experience.

Finally You need a good guide for this.

Heres a great resource:

http://www.healthspace.ca/Clients/VCHA/CoastGaribaldi/CoastGaribaldi_Website.nsf/e8db9633a9d595f988256b36000d14e7/210bfd06baf7620d88256f7f007e6469/$FILE/poolman03.pdf

Appendix 10 page 59 gives best dosage info. We have other resources, but this is one we use most.

SInce the pool store guys aren't chemists, you need to become the expert.

Finally, If you can find a bioguard dealer near you, I have found that they are well trained and have best test equipment. I buy their chemicals and everything happens as predicted.

The guys at the store that sells christmas trees and pool tables half the year and are swimming pool experts the other half don't know my name...

Good luck. be patient, and read the book I just sent you the link to.

milo "10 years on my pool need my sunglasses"

__________________
People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe
Register to Reply Good Answer (Score 5)
Guru
Engineering Fields - Mechanical Engineering - New Member South Africa - Member - New Member

Join Date: Aug 2006
Posts: 592
Good Answers: 40
#3
In reply to #2

Re: PH can not be raised to acceptable level

05/19/2009 4:03 AM

Had pools for 30 years in sub-tropical climate and can not fault your advice - GA

__________________
If you can't explain it simply, you don't understand it well enough. (A.E.)
Register to Reply
Anonymous Poster
#4
In reply to #2

Re: PH can not be raised to acceptable level

05/19/2009 11:34 PM

An excellent reply I must say Milo!

I've often had better results using liquid clorine for Shocking as it is already liquid and definitely contains no chalk or other filler as some granulated clorine does

Register to Reply
Member

Join Date: May 2009
Posts: 9
#19
In reply to #2

Re: PH can not be raised to acceptable level

05/20/2009 8:29 PM

Thanks Milo,

I am out of town for a few days but will try to improve my pool quality when I return. Is there unstabized chlorine products in granular/tablet form I can use or is liquid chlorine my only option? I operate the pool pump 6-8 hrs daily. The challenge I have with adding more soda ash, before doing anything else is my brain tells me the PH will not increase from prior experiences. My wife thanked you for your help, but did not sign in as ID Clark but Guest.

ID Clark

Register to Reply
Guru

Join Date: Jul 2006
Location: "Dancing over the abyss."
Posts: 4901
Good Answers: 240
#20
In reply to #19

Re: PH can not be raised to acceptable level

05/20/2009 8:49 PM

Calcium hypochlorite is a powder option, but it can also add to calcium hardness.

I bought a big bucket of Lithium Hypochlorite at a going out of business sale, a couple of summers ago. it is expensive but no other side effects that I know of.

As another poster commented, unscented liquid bleach is sodium hypochlorite.

The problem with this is that it is heavier than water, so it will sink to bottom of deep end and lord help you with your printed vinyl liner... so add slowly with pump running and stir the bottom up often.

Here are some additional facts about free chlorine anc cyanuric acid stabilizer.

http://www.troublefreepool.com/pool-water-chemistry-t628.html

The reason why we need a little bit of stabilizer in out door pools os to preserve the chlorine in sunlight. but too much works against the chlorine as the charts will show.

I'm traveling to Ft.Rucker Alabama to give away my 2nd Lt daughter's hand to another 2nd Lt. I'll be back next week as well.

Thanks to you and your wife for the follow up.

until next week.

milo

__________________
People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe
Register to Reply
Anonymous Poster
#21
In reply to #19

Re: PH can not be raised to acceptable level

05/21/2009 1:37 AM

Sure there are tablet and granular form of un stabilised chlorine chemical. It is calcium hypochloride, %70 available chlorine content. It has granular, big tablet and small tablet forms. They are not slow soluable like threechloro isocyanuric acid tablets so you can use it as chock chlorination or like dichloroisocyanurate granules. You can not use it to dozage your pool as you do it bu TCICA tablets. For this it has its own dispenser that lets pool water chlorinate continously. You better do not stop the pool motors unless you apply alum flucalant. If you are using TCICA or DCICA you better use polyaliminium with polymer fluculant. You need to check your alcalinity high enoug to form the flocks because TCICA and SDCIC does not have any alcalinity chemical like Calcium hypo or sodium hypo. You have to be carefull not to be over 20 ppm cyanuric acid in order to prevent chlorine block and wrong mesuarments. Tropical climate water loss by evapuration is usually high so CA will increase very fast. Keep the pool around clean. If possible use pool cover when its not in use for a long time. If you will not use the pool over 4 months, if your regulation permits add winter care additives. Link that is given is wonderfull, every pool owner should have it under his hand.

Hope this would help.

Register to Reply
Anonymous Poster
#5

Re: Problems Raising pH to an Acceptable Level

05/20/2009 12:11 AM

I was told a barium state of 7.2 ph is about as stable it can get to keep a consistant replenish... is this true?

Register to Reply Off Topic (Score 5)
Active Contributor

Join Date: May 2009
Location: Ontario, Canada
Posts: 21
#6

Re: Problems Raising pH to an Acceptable Level

05/20/2009 12:22 AM

I only use 3 chemicals and never have a green pool. Add your chlorine/shock, the first step is to kill the green stuff. I usually do this by adding the shock and some PH+. When the green stuff is gone the water is usually a little "mirky". Add a filter clarifier to your skimmer and this will clear the pool up. I don't even test until the pool is crystal clear. Keep it circulating like you would normally through the season. When your chlorine level has come done to just above the target level, test the Ph and add if necessary. If your PH is acceptable your chlorine will stay in the pool.

Some recommend adding an algicide at the recommended interval as well but i do not. I worked for a pool store one season. In the words of the owner "buy your chemicals from the hardware store, they're cheaper. The tests done by me are excessive, you're not drinking the water. Maintain the Ph and the chlorine will last longer."

Register to Reply
Anonymous Poster
#7

Re: Problems Raising pH to an Acceptable Level

05/20/2009 12:45 AM

Wow... Milo is on the ball here. Looks like reseach comes easy for some people.

I would have suggested something dumb anyhow, so I will let Milo's recommendations ride. THE ONLY thing I would ask/suggest is has the pool been recently retiled or refinished with old and nasty lye or banned chemicals?

If you can drink the well water and wash your hair (eyes) with it, then that isn't a problem. Did you call Al Gore? He knows about all things as he is all-knowing.
Obama said so... Or was that Al Gore who said so? Forget what Nancy Pelosi says...

JL Mealer
Mealer Companies LLC

Register to Reply Score 2 for Off Topic
Guru

Join Date: Jul 2006
Location: "Dancing over the abyss."
Posts: 4901
Good Answers: 240
#12
In reply to #7

Re: Problems Raising pH to an Acceptable Level

05/20/2009 8:07 AM

Good point about the resurfacing. My pools vinyl so it never ocurred to me about contribution of plaster...

Its not so much the research as the gut wrenching fear that you live through when you first get chlorine lock in your own pool and the choices are Dump the water, pay $200 to get new water trucked in (or pay $400 using your tap water and paying sewer taxes on the water bill) then pay anothe r$200 on chemicals for the new fill.

Or put in $100 worth of shock to add Chlorine to breakpoint chlorinate to destroy the chloramines. And your thinking my pool will glow after I add that much shock so you worry a couple of nights and then you grab a beer and just do it...

All kinds of corruption seems to boil out of the water and then you're done. two days later your back to total chlorine =3.0 and free chlorine = 3.0 and the water is so clear the FAA calls you about being a hazard to civil aircraft with reflected light and shine.

But that bet on $100 of shock ("do you know how much chlorine that is , man?" he tells the store owner in disbelief) vs ~$500 to start over is a real pistol.

milo

__________________
People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe
Register to Reply
Associate

Join Date: May 2008
Posts: 27
#23
In reply to #7

Re: Problems Raising pH to an Acceptable Level

05/21/2009 8:44 AM

Dear friends,

here I want you to remember that water balance is very important for all pools incl. vinil pools. All pool owners should pay attention to the water balance. Otherwise you always have risk of tile either loosing your tiles and dissolving your tiles and lost of your ceramics one by one and after a while your pool will start to drain from the pool walls or your ceramics or vinil will be covered by a calsium carbonate layer. This will couse many problem like lost of atraction, good home for algaes etc.

for the water balance there are 4 important value

1-pH, 2-total alkalinity, 3-calcium hardness, 4-temperature

2,3,4 enters the formulation as index but first pH enters direclty. so pH is a very important factor in water ballance and we can balance our pool water by changing the pH.

As all we know. There is a limit usuallt from 7,9 to 7,8 in our pools. This differance is given for to make our water ballance possible by playing with pH.

Factor finding:

temp factor alkalinity factor ca hardnes factor

0 0,0 5 0,7 5 0,3

12 0,3 75 1,9 75 1,5

19 0,5 150 2,2 150 1,8 etc.

formulation is pH+AF+CF+TF-12,1 = water balance index between -0,5 to +0,5

your water is said to be balanced and gives no damage or calsification on the walls of your pool. As you can see from the equation above by only playing with pH you can make your water ballance. with a example:

pH=7,3, Alkalinity=100ppm, calsium hardness=100ppm temperature of water is 28C

from the chart above we can find that

total alkalinity index of 100ppm is 2; same as 100 ppm of ca hardness is 1,6 we put them to the formulation

7,3(pH) + 2(AI) + 1,6(CI) - 12,1 = -1,2

This water is not balanced and will dissolve your tiles slowly. By making pH 7,8 this saturation index becomes -0,7 so it becomes save to use for your tiles and vinil.

Futher information can be find at the link belove

www.spasa.org.au/factsheets/Fact16.pdf

Hope this would help.

Regards

Register to Reply
Anonymous Poster
#8

Re: Problems Raising pH to an Acceptable Level

05/20/2009 2:30 AM

Hello, I will try to help you.

1, Recommended water index for Swimming Pools in the UK

ppm = Parts Per Million

1, Free Chlorine should be between 1.5ppm to 3ppm (5ppm Unless you are Shocking)

2, Total Chlorine Residue should be the same as your free chlorine level.

3, Ph should be at 7.2 for residential pools, or 7.2 to 7.4 for commercial.

4, Total Alkalinity should be between 110ppm to 160ppm.

5, Acceptable Calcium Hardness levels should be between 200ppm to 1000ppm.

6, Cynuric Acid (Stabilizer) Should be no more than 50ppm to 60ppm.

7, No phosphates should be in the water at all 0ppm.

8, Copper / Iron count should be no higher than 1ppm.

9, Sulphates no more than 300ppm.

When adjusting Ph or TA please allow 24hrs for adjustment to take place.

When lowering a TA it can take up to 10days with a Static pool water environment, (Pool Pump Off)

When Raising TA it should be done with a Moving water, (Pool Pump on)

When Adjusting Ph up or down. Always with Moving Water (Pool Pump on)

I would recommend that when you refill or top up your swimming pool, do it from your

house hold supply, or a fresh water running river not a well, as the well may have

some of your old pool water in it.

Actions to take, you started with a TA of 0ppm.

Total Alkalinity levels need to be set before you get an accurate Ph Reading

whats happens is as you try to fix your TA you will get what is called Ph bounce.

So the first thing you need to do is Bring you TA to in between 110ppm to 160ppm,

then adjust the Ph when you have a constant TA reading.

Please make sure you have a Free chlorine level at shock levels of 5ppm for the duration of trying to fix your water problems.

Please do not use any more Slow release chlorine to sanitise the pool water, As you have to much Cynuric acid in the pool water, the only way to fix this problem is the dumping of water from the lowest point of your swimming pool.

The only two chlorine products which do not have Cynuric Acid in is:

Liquid Chlorine (Sodium Hypochlorite)

Shock Granules ( Calcium Hypochlorite)

You have enough stabiliser in your water to last you two years with frequent back washing for the filters from the lowest point of your Pool.

When using Liquid Chlorine, it will naturally push the Ph of the Pool water up, as Liquid Chlorine has a high Ph factor Please bear this in mind.

Please use TA Plus to raise The TA, I would suggest that you test approx every 12Hrs & make notes to refer to, as your TA adjusts to the right level your Ph readings will be more accurate.

The next Problem you have is the Phosphates in the water.(Phosphates are Algae food!!)

You need to ask for a Product called Starver, what Starver does is it Pushes the Phosphates in to calcium. the funny thing is your pool basically wants calcium at the moment!!

I would suggest that now is the right time to use the starver, simply because your Ph & TA are low & Acidic water loves calcium, so the water will absorb the calcium as the starver forces the phosphates in to calcium.

I would recommend that you do use a liquid clarifier to clarify the pool water at any time the Pool Water is looking cloudy. clean your filters regularly.

You will find dose rates of any product on the labels of chemical products.

Caution Never Mix Any Chemicals together, always dose you pool with any chemical one at a time, Either directly straight in to the pool water or add chemical to pool water in a bucket, Always read the instructions on the containers of any chemicals & follow them out carefully.

Best of luck, I hope this info helps you.

Register to Reply Off Topic (Score 3)
Associate

Join Date: May 2008
Posts: 27
#9

Re: Problems Raising pH to an Acceptable Level

05/20/2009 3:52 AM

You have not metion what kind of clorine chemical you are using. Total chlorine do not mean anything unless with free chlorine. When you have free chlorine over 1 ppm there is no possibility to have any combined chlorine. I am almost sure that you have a chlorine lock in your pool due to the high level of stabile chlorine chemical like sodium di chkoraiso cyanurate. According to my experiances this can be the only reseason of your problem. I advise you to use un stabile cholrine chemical like sodium hypochloride or calsium hypochloride until you Cyanuric acid lavel fall to 20-30 ppm and keep it like that with using unstabised chlorine chemical together with stabilised one. Prefer to use sodium di chloraiso cyanurate instead of threecholora iso cyanuric acid(it increase the cyanuric acid content much more than the other). I dont know is it allowed in your country to use anti algicid in sweeming pools. If it is okay use it. It will help to cure your pool much easy. If you are using three cholroisocyanuric acid and choline chemical its very normal that you can not be able to increase your pH because it gives continously acid to your pool. Using sodium hypocholride for chlorine chemical it will higer your pH with in this time and water will be balanced. Do you have chanceable cartrage filter media or you make back wash to clean them. This is important to know how much fresh water you get to your pool.

If there is any thing that I can help please ask me.

Best withes with clear pool.

Hasan Arsan

Register to Reply Off Topic (Score 5)
Power-User

Join Date: Aug 2006
Location: Central Florida in the good old US of A
Posts: 332
Good Answers: 2
#10

Re: Problems Raising pH to an Acceptable Level

05/20/2009 5:48 AM

Milo,

Great answers; added your info to my home pool help folder and gave you a "good answer" vote. One last thing, is to check the age of the test kit. They don't age well and can give poor results if old. I had this problem not long ago. Plus, I keep mine in the house to control the storage temp better than outside. I would assume the pool store to have up to date test chemicals since the go through so many in their daily water test routines.

__________________
Eschew obfuscation.
Register to Reply
Commentator
Engineering Fields - Control Engineering - New Member United States - Member - New Member Popular Science - Weaponology - New Member

Join Date: Jan 2009
Location: Berkley MA
Posts: 88
#11

Re: Problems Raising pH to an Acceptable Level

05/20/2009 7:36 AM

Another issue which I found is that the testing kit chemicals do have a shelf life. I use a liquid based testing kit because I find that it is more accurate than the strips. I do agree with Milo in that the pH level needs to be addressed first, then tackle the Alkalinity. Even though I have a DE filter, upon opening the pool I run the pump for 24 hrs for two days and then back off two hours every succeeding day after that until I get to about 8 - 10 hrs a day (With Milo's suggestion of circulation will help with chemistry plus it will help prevent alge build up.) This length of time is dependent upon your area. With the Cyanuric Acid, this will definitely affect your pH and your chlorine content. I would begin with shocking the pool and run the pump consistantly for 24 hrs after. Then I would deal with any pH variations.

Oh and the topic of pool salesmen, the ones that are seasonal stores are not worth talking to. I deal with a reputable pool company. Contact the BBB to find a reputable company and build a relationship. Often, they will test water for free and offer free advice. Also, they will have all of the applicable chemicals that you will need.

Don't give up hope and good luck

__________________
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.
Register to Reply
Associate

Join Date: May 2008
Posts: 27
#22
In reply to #11

Re: Problems Raising pH to an Acceptable Level

05/21/2009 5:45 AM

With liquid test method you mean ortotoluide method which is a light yellow color solution. This method gives only total chlorine in the pool which is free chlorine and binded chlorine. This method does not mean much and usually couse missing results. For my experiances best method is DPD tablet tests which with DPD 1 tablet you can find your free chlorine and with DPD3 tablet you can find your total chlorine and the differance between gives you all the chlormine in your pool. When you keep your free chlorine level 1-2 you should not have any chloramine in your pool which gives chlorine oddor, decaying bath suit, changing hair color and irritation on the eyes and sessible skin parts. When you have 1 ppm free cholrine measured by DPD1 you can not feel any chlorine effects in your pool. If you are working with 0,3 -0,5 ppm there is always risk of having chloramine in your pool and you can feel it.

when you have nitrogen containing human derivatives in your pool chlorine reacts them like that

N containg human derivatives + Cl2 =monochloramine very irretant

ıf you have enough CL2 they turns to dichloramine very irretant and smell of chlorine

if you still have more Cl2 in your pool trichloramine which is also very irretant and evapurates give extensive chlorine smell.

if you still have more Cl2 then they all turns back to N2 and leaves your pool without any irretation.

when people enters the pool its secrates urine containing products to the pool water with out knowing it. Childeren, old men and women have more tendency to this naturally. This is why Cl2 is still most important additive for cleaning and desenfectation for pools. If you treat well there is no problem of this. Free chlorine complately eliminates them.

Register to Reply
Participant

Join Date: May 2009
Posts: 1
#13

Re: Problems Raising pH to an Acceptable Level

05/20/2009 9:14 AM

This is my first time on the forum. I can understand your frustration with the pool problem.

I had a similiar problem a few years ago with my pool - same circumstances.

The first thing you need to do is get rid of the "green tint" this is green algea, try shocking with chlorine until the water is clear. add algeaside to balance. then after cleaning the pump, start to work the p.h. level. You will go crazy trying to do the p.h. without first controling the algea problem.

I also partially filled my pool with my well it was slow but effective. Just a tip to consider that some local fire companies depending on your area, will fill your pool and use the experience as a training drill for newbies - worth a shot. total cost is based on a contribution to the fire department ( $50.00 - $100.000) your call.

Good luck and I hope this helps!

Rick

Register to Reply
Member

Join Date: May 2009
Posts: 9
#24
In reply to #13

Re: Problems Raising pH to an Acceptable Level

05/24/2009 3:20 PM

Thank you for your help. I need all I can get.

Register to Reply
Participant

Join Date: May 2009
Posts: 1
#14

Re: Problems Raising pH to an Acceptable Level

05/20/2009 1:30 PM

You a going to need to shock your pool to kill the algea growing in your pool water. Is the pool covered? Covering the pool with an opaque cover will reduce the growth of algea.

To shock the pool to reduce kill the algea and eliminate the combined clorine you need to add enough clorine to raise the levels to 10x the current total clorine levels. For example if the total clorine is 3ppm you need to add clorine to reach 30ppm.

If the alkalinity is were you want it, you could try aeration of the pool water to raise the PH level of the water. The easiest way to do this is to make a sprayer which attaches to a return line and sprays onto the water surface. This agitation causes carbon dioxide to be released from the water raising the PH(The PH is raised due to reduction of carbonic acid present in the pool water). The reason for using aeration and not more chemicals is that the akalinity should stay constant as the PH slowly increases.

I would suggest that you by a good quality liquid test kit such as the ones from Talor Technologies. I had a real problem maintaining correct balance until I got my own accurate testing solution. Running back and forth to the pool store is very frustrating and usualy results in your spending excessive amounts of money on unneccesary chemicals.

What is the pool contruction? Cement, Vinyl liner, etc.

Register to Reply
Member

Join Date: May 2009
Posts: 9
#25
In reply to #14

Re: Problems Raising pH to an Acceptable Level

05/24/2009 3:24 PM

Good comments, THANKS

Register to Reply
Anonymous Poster
#15

Re: Problems Raising pH to an Acceptable Level

05/20/2009 5:07 PM

Some good answers no doubt, but I'll tell you a couple of things based on 20 years in the pool industry. At 70 - 100 parts cyanuric, you chlorine is not "locked" and that is a questionable theory anyway. Go ahead and use liquid chlorine (sodium hypochlorite) to raise the chlorine level to 5ppm or above and that in itself will pull your pH up. Circulate the pump 24 hours/day and maintain by adding more liquid chlorine until your pH is 7.4. At that point, if your water is still discolored then shock with 10 pounds of calcium hypochlorite (granular chlorine).

Hope that helps.

Register to Reply
Guru

Join Date: Jul 2006
Location: "Dancing over the abyss."
Posts: 4901
Good Answers: 240
#16
In reply to #15

Re: Problems Raising pH to an Acceptable Level

05/20/2009 5:40 PM

The recommended range of Chlorine in a pool is 1-3 ppm; (google will give many links)

In the first step of the process, You recommend taking chlorine up to 5 ppm.

Then you suggest adding more liquid chlorine (unknown quantity) to raise pH to desired level. Lets be stingy and say that raises Chlorine to 7 ppm. Liquid chlorine will not have cyanuric stabilizer).

Then, you suggest adding ten pounds additional calcium hypochlorite shock, Which I presume will be about 13 or 14 ppm figuring 7.8 pounds equals 10 ppm in a 24000 gal pool.

13 plus 7 = 20 ppm.

Congratulations, you've just acheived "questionable theory" breakpoint chlorination.

As was suggested earlier.

If That 20 ppm doesn't get reduced by destroying those chloramines as held in that "questionable theory," At what point will the pool at 20 ppm to be safe for humans to enter?

milo

__________________
People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe
Register to Reply
Anonymous Poster
#17
In reply to #16

Re: Problems Raising pH to an Acceptable Level

05/20/2009 6:23 PM

Sorry MILO, I will speak s-l-o-w-e-r for you. Bring the chlorine back up to 5 ppm with liquid chlorine. The next day, test and add if needed more liquid chlorine (probable), and so on, until pH is in a 7+ normal range -- thus relieving this man of his acidic state of trouble. The green tinge is a temporary inconvenience at best and will probably be relieved by the time the pH hits 7.4. More than likely swimming by the weekend. I think I hit a nerve with the chlorine lock statement.. sorry. Truth hurts.

Register to Reply
Member

Join Date: May 2009
Posts: 9
#26
In reply to #17

Re: Problems Raising pH to an Acceptable Level

05/26/2009 4:37 PM

Thank you for the advice. I appreciate all the help I can get.

Register to Reply
Associate

Join Date: May 2008
Posts: 27
#27
In reply to #15

Re: Problems Raising pH to an Acceptable Level

05/27/2009 2:28 AM

70-100 ppm cyanuric acid level is a very critical limit for chlorine lock. As you know cyanuric acid test based on turbidity measurments and usually very difficult to see the right point of this turbildity. Real cyanuric acid level usually much more than what you measure in your pool. many conditions are effecting the real turbilidity turn point. I never keep cyanuric acid level over 30 ppm and had no problem. In hot season places accumulation of cyanuric acid increase too much due to the evapuration of water from the pool.

I dont know what kind of filteration he has. Cartrage filters are usually changeable so no back wash like we do in sand filters. If there is no back wash of filter he need to replace some of the water like he do back wash. Pools need some fresh water to replace themselves. As far as I know cartrage filters do not allow to use flucolant to make the water clear. in such conditions and when I need to use alum fluculant after I add fluculant I let the pool work 2-4 hr without filtercartrages and then close the pool and let it sattle down and vacum clean by discarging the water directly our to dranage. Be sure that if any alum fluculant left in the pool those will clog the filters.

I strongly advise to use sodium hypochloride (bleach) until the cyanuric acid level falls to 10 ppm. You will see that your pool will be clear and safe. I didnt have any problem from well water (very hard water) by controlling the water balance. If you want a quick result you can use HEDP (Hydroxyethane-1,1 diphosphonic acid) as cleating agent. Dont use any other cleating agent because HEDP have great resistance to free chlorine. This is not necessary if you are able to control your water balance by your pH. This is necessary if you are not able to set your pool water balance between -0,3 to+0,3 by your allowable pH in the pool.

I manufacture 5 years pool chemicals and service to the pools from olympic pools to small pools and find out that most of the problems in the pool comes out from mechanical problems than chemical problems and as far as you try to solve them by chemicals you increase the problem so its best to starat from a mechanical check to a problem. If you are keeping cyanuric acid level max. 30 ppm, free chlorine level min. 1 ppm and water balance between -0,3 to+0,3 max. you cant have any chemical problem and also you should not allow to enter any oil to your swimming pool. ( from sun screen creams and oils). Now a days water resistance sunscreen products are great problem for the swimming pools because you can not get them out by short shower and they get in to the pool easly especially ones who use algicide(quats) in the pools.

Regards

Hasan

Register to Reply Score 1 for Good Answer
Anonymous Poster
#28
In reply to #27

Re: Problems Raising pH to an Acceptable Level

05/27/2009 10:00 AM

Sounds good, but again I beg to differ. In Texas we consistantly run 20 - 50ppm cyanuric acid levels to combat the chlorine loss to sunlight in commercial pools -anything less will only make consistancy near impossible. It is a common practice for residential service companies to run 100ppm (and add to reach that upon taking on a pool) so that they can maintain residual until the next visit. The question and problem was related to low pH - not chlorine "lock". I've seen some beautiful pools with 200ppm stabilizer levels, though that is well known to be above acceptable levels.

I fully agree that the use of sodium hypochlorite will help with both issues. I actually prefer 20-40ppm, but it is so commonly found to be much higher in your average tablet feeding backyard pool. Oh well.

Register to Reply
Anonymous Poster
#18

Re: Problems Raising pH to an Acceptable Level

05/20/2009 7:59 PM

Hi Back, to all of you helpful people out there. The information sent about raising the PH of my pool will hopefully help to get this "challenge" fixed. I am out of town for the next couple of days so trying some of these methods will be number 1 on my list when I return home. Thanks to all of you for taking the time and effort to help me with this. We have used the 3" chlorine tabs for years we use 2 bags of "shock" at least once a week and run the pump 6 to 8 hours a day. We have had problems raising the PH for several years now. It's a constant,frustrating, expensive battle. Chemical test solutions have been replaced with no change in readings. Do you recommend the "test strips" or the liquid chemical for testing purposes? I feel like I walk into the "pool store" and am at the mercy of the "boys" working in there. Many just say "add" more of this or more of that!!!!! I will let you know the results!!

Register to Reply
Register to Reply 28 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Anonymous Poster (9); arsan50 (4); bsnider (1); ID Clark (4); InstrumentKyle (1); Kyoto (1); lyn (1); Milo (4); NukeGeek (1); Stryker (1); The Prof (1)

Previous in Forum: How internal lubricated silicones affect viscosity?   Next in Forum: Rarefaction of a Gas
You might be interested in: pH Electrodes, pH Transmitters, pH Instruments

Advertisement