That's a big pool (2-3 times average, I'd guess) so you're going to use more of everything. That said, your acid use still seems a bit high.

What pH are you trying maintain? There's nothing wrong with running pH at the high end of the 7.2-7.8 range, especially if your pool "wants" to settle up there. Are you trying to keep it at the low end of that range?

Is this a new gunite/plaster pool? If so, the curing plaster will drive up pH for the first few months.

Do you have an SWG? If so, your constant pH rise may be being caused by that.

Do you have a lot of water features such as waterfalls or fountains? Ditto.

What is you alkalinity? If that's too high it can also put upward pressure on pH.

Keeping the PH 7.4-7.6 because we had a problem with the midnight blue diamond brite discoloring. We were told by SGM and others it was due to scale and we needed to keep the PH on the low side to keep it from continuing. Since the acid wash late last season I've been spending a lot of time and money keeping it at about 7.4 but it does not seem to matter the color faded and continues to fade or scale.

Gunite pool 1 year old, we were told the acid demand would be higher for a new gunite pool so that made sence the first season.

We do have SWG and I had heard that might create a demand so I recently turned it off and used liquid for a week It seemed no different. Maybe I needed to leave it off longer to see if it made a difference?

We do have a large gunite slide and large waterfall that get used 2-5 hours a day depending on the kids and how hot it is outside.

During the winter acid demand was about 1 gallon per month. Since opening this season demand has been about 1 gallon per week and seems to be the same as when the pool was new. Although we are using the slide and waterfall more since it has warmed up.

TA runs 60-80

We have a 30K gallon salt water 1 yr old and we uses 1 gallon of acid per week

We have a SWCG pool that is around 10K gallons and as previously mentioned, we have a constant rise in our pH. I use around 1 gallon of acid every 4 - 6 weeks. However, acid is the only thing I have had to add since finishing our pool last June. At $7 bucks for two gallons at my local Leslie's, I consider it to be quite a bargain!

Regards,

Mike

Update- I mentioned to my next door neighbor who has a 25 year old 28K gallon gunite pool that I was using a gallon of aicd per week and he about fell out of his chair and said there must be something wrong. He claims 1 gallon a year and on cool years none at all. He suggested something might be wrong with my tester so I brought both my test kits over and tested and used his tester and he was 7.4 on all 3. He says he put in only 1 cup this season a few weeks ago. He also said the neighbor accross the street with a slighly smaller pool than his never uses acid. Neither have water features and neither have SWG.

Could this much acid demand be caused by the features and SWG alone. Are the new gunite pool and water features still curing? Am I missing something else that might be causing the demand? Or is this really all normal.

I don't have any input, but I'd LOVE to see pics of your pool ctiguy...THANKS:)

Slide

Water Fall, slide, and spa

Beautiful pool! We have a new and small app 14.5x30 13,000 gal (plus app 600 gal spa)SWG pool with PS at our FL home. Our NV home has a common area liquid pool and it always seems like the pool guy is out there adding things(and draining the HOA funds) Just added salt for the first time about two weeks ago and started up the SWG after the PB was maintaining it on tablets. Our pool school guy and pool shop owner said (and like others here have said) it is somewhat "normal" for a SWG pool to run on the high side of the PH scale. Had the water tested a week later and the PH was 8.0. Everything else was in range. :-) Was instructed to add 1.4 qts of acid diluted app 5 to 1 with pool water. Left the store only out $3 :-)

"However, acid is the only thing I have had to add since finishing our pool last June. At $7 bucks for two gallons at my local Leslie's, I consider it to be quite a bargain!"

Yesterday my wife had the water retested at our local shop and PH was 7.7 and everything else was in the normal range again so can't complain here either. :-) Maybe things will change once the waterfall is added. Never expected to get out of the pool shop without a cart full of stuff.

I was almost ok with the SWG cost vs convenience. If it is causing me to have to purchase and store and add that much ACID it seems as though it might not be worth it. Being that our pool is so large and the SWG can't keep up with it in the middle of the summer, I don't see why I would replace it when it wears out(soon as I am running 100%) or even continuing to run it.

Anyone out there turn their SWG off and convert to bleach?

ctiguy-
If your pool is 45K gallons, one SWG is not big enough for it, therfore you will have problems keeping up with demand.
Your PB should have known this!
You would need 2 SWG for that big of a pool.

Steve

Steve,

So would I need to add even more acid with 2 SWGs. Lets see another $1K for a SWG and more acid. Hmmm this cost over conveneince thing is not working out so well.

Has anyone turned off their SWG and thought it was a good move?

FWIW, 3 homes on my street have pools. None of them have SWCG's. All are converting this summer after swimming in our pool. If the acid demand is causing this much inconvenience, switch to something else. I prefer the SWCG, simply because my skin doesn't get dry, my hair doesn't get damaged and I don't smell like a public pool when I get out.

skinnydipper

OK this is interesting. How does a SWG provide all these benefits?

I thought the SWG simply used electrolisys to pruduce bleach from salt water.

In my previous residence when the SWG cell burned out I used bleach for a month till my pool service finally fixed it ($600 for a new cell and install) I noticed no difference. Maybe it was different but I was not looking for or expecting a difference.

If I may chime in here...I believe that you wouldn't have noticed a difference when your SWG was offline because you still had a salt(ed) pool. Saltwater is what makes your skin feel nice and minimizes dryness. Most people can tell a difference when going from a "regular", non-saltwater pool to a saltwater pool, with or without an SWG.

There's been some discussion on another forum regarding the benefits of adding borates to pools with SWGs to minimize the pH rise. But it sounds as if getting a second SWG might be the first order of business.

Here is a link that might be useful: Borates, SWCGs, & pH

ctiguy,
I think your SWG and water features are the main culprits here. Both cause carbon out gassing which leads to PH rise. The relative newness of the plaster may also be a contributing factor.

What is the calcium level in your water? With the low pH you've been keeping and the low TA, I sincerely doubt you've had any scaling; to the contrary, I'd imagine your water is somewhat corrosive.

We're pretty close to the limit of my knowledge on this. I suggest you post your question, along with all the relevant chemistry numbers, at poolforum.com (if you're already a member there) or at troublefreepool.com if you're not a member at poolforum. chemgeek, a regular contributor to both those forums, will be able to help you.

SWGs are the best things since sliced bread! But they do
rise Ph. A small price to pay.
We had a small pool/spal 6K gals. on our 4th year I added
a Pentaire IC20 swg. I ran it at 20% 6hrs a day with a constant .5ppm chorine.(fantastic!)(no more chorine Jugs or Tablets)
Prior PH constatly stayed a 7.4 (fantastic!) Now after the
SWG it climbs to 7.8 in a week.This requires 2 cups of acid
a week,beats the heck out of jugs of chorine!

Will be putting a SWG in our new house/pool.Builder price
is $2500.Will cost me a few hours and $500.DIY. Same with
heat pump builder $4500./$2000. DTY.

JR....

PS...Pool Pilot/Auto Pilot has a model that adds acid as
needed from a tank on it. But is very pricey.

ctiguy,
As you know the SWG does not provide any of the benefits listed. It is the salt for soft skin, proper pool chemistry for your hair and don't compare a public pool to a backyard pool. A public pool has way to much going on and thus must have mega chemicals added all the time.

I'm not saying a public pool is the same as a backyard pool. It's the smell of chlorine that reminds me of a public pool. The smell is all over your body and in your hair when you get out. The liquid chlorine used in pools does cause blonde hair to turn green, I know from experience. It also causes your skin and hair to become very dry. This is why I choose to use a swcg. I never said anyone should do as I do, I simply said if the inconvenience of adding acid outweighs the benefits of a swcg, then switch.

The metals (copper, iron, and manganese) are oxidized by the chlorine and then bond to your hair, causing the greenish hue.
Same would happen in your pool if metals build up

skinny,
Neil's right. Green hair is caused by copper not chlorine.

The postive attributes of your SWG pool such as the "feel" of the water, no stinging eyes, etc. are a result of the salt in the water, not the SWG.

The "chlorine" smell in public pools results from too little free chlorine to get rid of the combined chlorine (chloramines). You could get that smell in your SWG pool if you didn't maintain high enough chlorine levels and had a high bather load; it's just not likely because you don't typically have 15 or 20 sweaty kids who are putting things they shouldn't into the water.

Chlorine, is chlorine, is chlorine once it's in the water.

Speaking of chlorine :) someone posted the bleach calculator recently and I can't seem to find it. Can somebody repost that link? Thanks.

I have an AutoPilot SWG with a vinyl liner pool. I found last year that when my TA and CYA were on the low end I added acid every week or 2. I decided to raise them up to the higher end of the recommended levels and found I was adding acid every few days. I am no chemist and really don't fully understand how these values affect each other but I know what I experienced. With a plaster or gunite pool things may be different.

We had a discussion about this some time ago "Dude, I'm dropping a lot of acid!" or some such.

Pretty much, we decided the swg causes the phenomenon, and perhaps it's some pebble too.

Either way, I've got about 17 or 18,000 gal's and use 1/2 gallon a week, at least.

Ralph

Well I have a vinyl liner pool, ruffly 22,000 gallons. We have been getting plenty of rain here to where I had to backwash recently. Just yesterday after our kids and buddies got done, I re-tested the pool and I only needed 2 cups of Acid. Oh yea, I did not have to do this till about about 1.5 months ago :)

Update- Adding ACID 2-3 times a week is killing me. In order to add the ACID I need to shut down the SWG or it might get damaged. The problem happens when I forget to turn the SWG back on after waiting for the ACID to mix in. Almost immediately I get a batch of algae on my rocks and very little if any CL reading. Then I need to add some bleach, scrub off the Algae off and vacuum

Has anyone damaged a SWG by adding ACID to the pool while it's running?

Adding acid to your water while the pump is running won't hurt your SWG. Just dribble it in slowly in front of a return or a little at a time around the perimeter.

My Jandy SWG Manual(see link below page 28) says- Do not add any pool water balancing chemicals (including salt) unless the AquaPure is turned off.

I had a problem with my Aquapure last year when it was only a few months old and had to get it replaced. The tech that replaced it said it could have been damaged when I was adding acid. He said I should never add acid while it was running and pointed me towards the manual.

Has anyone else been told not to add acid while the SWG is on? Or been told adding acid while the SWG is runnning caused a unit to go bad?

Here is a link that might be useful: Jandy Aquapure Manual

I don't understand how it could damage the swg...I have Goldline Aqualogic...you clean it by soaking it in rather high mix acid/water...how does that make sense?

Anyway, I recently drained half the pool and refilled due to high calcium hardness. I've been adjusting all chem's including a gallon a week of acid while the pump and swg are running. I add above return farthest from skimmer and suction points, and make sure the navigator isn't immediately nearby. I also turn on the water features to maximize circulation and even distribution as quickly as possible.

Having a "cell power error" w/ swg currently, but Goldline rep doesn't see an issue w/ my chem method. Is Jandy that much different?

Hope you can solve the prob...

Ralph

The tech that replaced the unit said something about adding ACID to Chlorine casuing a reaction.

When you are cleaning your unit with ACID I would imagine it is not connected and not making chlorine at that time. So there would be no risk of adding ACID to chlorine?

Sometimes warnings are CYA for companies and if I understand the issue and the risk, I can be careful and bend the rules a bit. Not sure on this warning but it is making life hard on me and my pool chemistry.

I don't remember enough college chem to know if that sounds right...is muriatic acid differnt than hydrochloric? Anyway, figure if you dilute the acid into a five gallon bucket then dump in...s/b ok. Figure scoop 3-4 gal's from pool into bucket, add acid to that, then dump back in. You'll be diluting 8 to 1 or something, so s/b just fine. Don't see how you'd need to turn off for this mixture.

Best...Ralph