Low pH and High Alkalinity

[Allen G Myerson]

Unfortunately, there are few options to having a high cyanuric acid level.

Some areas have reverse osmosis treatments available. Reverse osmosis is only available in a limited number of locations, like southern California and Arizona. Check around in your area for availability.

Another option is to add sodium bromide, which would convert your pool to bromine. Bromine does not combine with cyanuric acid. Once you add sodium bromide, the process is pretty much the same as chlorine. You just add bleach on a regular basis to oxidize the bromide to bromine. You won't get much sunlight protection from the cyanuric acid, but you will get some.

There is a bacteria that some people get that converts cyanuric acid into ammonia, but that's really not a treatment option.

Draining and refilling to dilute is usually the best option. You should be able to use your well water unless it contains a lot of metals, such as iron.

[Allen G Myerson]

Also, do you have a heater?

Is there any copper in the water?

Have you ever used any type of copper product such as copper-based algaecide or an ionizer?

Remember that you have to subtract one third of your cyanuric acid level from your Total Alkalinity to get your Carbonate Alkalinity. You want to get your Carbonate Alkalinity to about 100.

[Guest]

I live in the Chicago area
I do have a heater.

It willbe expensive for me to change out the water. I dont think I will do it this year because the season is almost over. When the company opens the pool next year I will drain it down more and get water trucked in. Everything I have read is to get new water. I wish I knew all this before hand. A pool seems more complicate dthan a thought until you learn about all the chemicals
The compnay insists on people doing the schedule I do. Some of friends barely do anything to their pool and theirs is crystal clear. what a bummer.
I have never added anything copper.

[Allen G Myerson]

Why can't you use your well water?

[James Watson]

You're better off dealing with this as soon as possible. Bad chemistry can damage your pool and equipment.

At least get your alkalinity down. Add enough acid to lower the pH to 7.2, and then aerate to raise the pH. Keep doing this until your alkalinity is at a good level.

[duraleigh]

Ditto what James Watson said above. You would be at risk of damage if you left it over winter.

[Guest]

I drained the water to about a foot left in the shallow end as I am going to try an dfix the cyranuric acid level. I haeve lots of alage in the pool since the last couple days.

I am having the water trucked in- any advice to get this pool crystal clear again as the new water is being dumped in

I will check all the chemicals tomorrow evening.
Should I dump liquid chlorine in? how many gallons?

[James Watson]

Get your pH down to about 7.2 and use liquid chlorine to raise the chlorine to about 25 ppm. Maintain 25 ppm until this clears.

You are going to need an FAS-DPD test kit to measure the chlorine at these levels.

If you get a chance, please post a full set of new readings.

[James Watson]

You can use the pool calculator to calculate how much regular, unscented 6 % bleach or liquid chlorine to add to increase your FC level.

[Jimbo]

If you use Tri Chlor tablets and tri chlor shock and have a strong residual at time of testing it could give you a false PH reading so let the chlorine levels fall and retest. Have it tested at the pool store too as the cheaper home test kit solutions are not as accurate. Try using liquid chlorine to shock and tabs to maintain proper chlorine levels though you will need to use acid but this seems to keep total alkalinity more in line over the long run.

[James Watson]

Try using liquid chlorine to shock and tabs to maintain proper chlorine levels though you will need to use acid but this seems to keep total alkalinity more in line over the long run.

The poster was using tabs. That is what caused their cyanuric acid to go too high in the first place. Tabs would be a bad choice. Also, tabs are acidic, and require the use of pH raising products, not acid.

[duraleigh]

Not to glom on but James Watson has it right. Do NOT use any more tabs!!

[california]

Sounds like I too have been using too much tabs. I went away this summer, left the wife in charge of the pool. I told her to just use the tabs. Algea got outta control so I told her to use more tabs. Cleaned the DE filter when I returned, SUPER SHocked and it cleared up. Couple of weeks later the algea crept back then exploded. Over the last couple of days I have put in 4 gal of liquid Cl, 2.5 lbs of shock 30 oz of algecide. I cleaned the DE filter again, still lots of algea in suspension. I'm really suprised all the CL is used up. Seems like I have added plenty.

I hadn't been checking the ph so
I did that today and found the following:
Total Cl .5
Free Cl 0
pH 6.8
Total Alkalinity 240
Cyanuric Acid 150/300

35,000 gallon pool

I just added 2 gallons Cl. Free Cl has moved to 3 same with the total Cl.

Should I dump another couple of gallons of Cl? The pool looks like lime aid.

How should I balance the alkalinity with the low ph?

[chem geek]

I wouldn't worry about the TA if the pH isn't rising too fast. You're going to need to do a significant partial drain/refill to lower the CYA anyway and that will likely lower the TA depending on the TA in your fill water. I suggest you read Defeating Algae, but note that it takes a lot less chlorine for shocking the pool if your CYA is lower and you're going to eventually need to lower it anyway so might as well do that now.

The following are chemical facts that should be disclosed:

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 at least 7 ppm.

So even with a low 1 ppm FC per day chlorine usage, using Trichlor as the only source of chlorine would raise the CYA by over 100 ppm in just 6 months if there were no water dilution.

[california]

...You're going to need to do a significant partial drain/refill to lower the CYA anyway and that will likely lower the TA depending on the TA in your fill water.
The following are chemical facts that should be disclosed:

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 at least 7 ppm.

So even with a low 1 ppm FC per day chlorine usage, using Trichlor as the only source of chlorine would raise the CYA by over 100 ppm in just 6 months if there were no water dilution.

Yeah, that's gonna be some trick. I don't have a backwash on this pool so I don't know how I'm gonna dump the water. Maybe run the water out the filter with the top of the DE filter removed. then it can hit the deck drains and hopefully make it to the gutter. I haven't done a drain down in the 4 1/2 yars I've had this pool so maybe it is time. I added another gallon of liquid Cl since my last post. Started the sprinkler pool feature.

Yes I belive I have been schooled quite well today on the conditioner build up. Thanks its great info and finally I understand.

I am a little curious about the aeration and how that affects the alkalinity.
anyone care to explain or link me to an explanation?