High PH rise? High CH. SWG plaster, Vegas!

BigMouthStrikesAgain

Well-known member
Aug 30, 2017
50
Las Vegas
Long Story!

After all of the advice I've gotten from this site (THANK YOU!) my main objective has been keeping track of my PH. Adding MA every few days. averaging about 8oz per day this summer in a 6,000 gal pool. Since this seems to do the trick, I was thinking about buying an automated system that would add the MA on its own.

After researching IntelliPH, I called my pool builder to pick his brain about the system and to get a quote. He had never heard of it. He has had his pool business for 20+ years. He referred me to one of his employees who might know about the product. This person told me it is not a big seller and he has reservations about the IntelliPH. His main concern is adding another element which could potentially break. I think it was an odd conversation, he wasn't trying to upsell or sell another product to me. When I told him I add aprx 8oz a day he said it was way too much and that I need to get my TA in line because it is too high and I can't get an accurate PH reading. Well I hadn't checked TA in 3 weeks but did not think it was high. And how would he know over the phone what my TA is? He is the guy who opened my pool with 50% too much salt after all!!!

so without further ado, today's numbers:
PH 8.2. (it was 7.5 two days ago. Since I was going to work I added 8oz MA. Two days later it's at 8.2!)
FC 6.0. (I set my SWG at 40% most of the summer. Somewhere between 20-40% works)
CC 0.0
TC 6.0
CH 1075!
TA 60
CYA 40
SALT 3800
TEMP 85
CSI .79 (It would be .11 if PH was 7.5. It would be .01 with a CYA of 70 and ph 7.5)


Some notes:
Due to last year's problem of too much salt in the water, we had the entire pool drained in January. I brought the salt level up to 3200ppm. I understand it goes up as temp goes up. I never added any more salt.
In April, the SWG crapped out. Pentair came out and installed a new one. This one requires 3600ppm not 3400. Since the temp was climbing I added no salt.
My CYA was at 70. I was under the impression you can not lose CYA. I also understand you cannot get rid of cya without draining water.
CH is very high. It has always been high. CH in fill water is high too. I thought that CH being high was OK provided every other parameter is normal.

So today I added 16oz MA and brought the SWG down to 20%. I believe I will have a ph of 7.5 tomorrow and FC of 5.0. If everything else remains the same, my CSI will be .11 and that might be OK considering such high CH.

If it matters I cleaned the pool filters and salt cell Aug 17 and on Jun 2.


So what I am asking is for opinions on my chemistry? What steps to take to get it back in line? I do not believe I can recover the CH. But maybe the CSI? How about adding more CYA - I am scared of having too much. Any one use the IntelliPH?

Thanks as always
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,449
Laughlin, NV
I assume you have LVVWD supplying your water. Most likely Colorado River water. So your fill water should be ~250 CH and ~130 TA.

Your CH is at the point I drain and refill. Takes about 18 months for me. Your timing sounds way to fast to me. Are you sure Cal Hypo was not used as a 'shock' by a pool maintenance company?

CYA is oxidized with high water temperature. We have that from June to September. I lose 10-15 ppm per month. So you need to test it and add some CYA powder or use a puck or so every month.

Keep your CSI under 0 or you will have scaling in your SWCG.

- - - Updated - - -

I use 8 oz of acid twice a week. So I also think your pH is going up too fast. Any water features?
 

BigMouthStrikesAgain

Well-known member
Aug 30, 2017
50
Las Vegas
Hey,

I checked my notes. January 2 we drained the pool. I then checked the chemistry of the fill water. You are right on the money, it read a CH of 225.
Cal Hypo was not used as I am doing the pool maintance and don’t know what Cal Hypo even is. I lost my faith in pool companies - a story I can share another time.
You and I have the same size pool. And I am using about 4x the MA!
The only feature in the pool is a “sun deck” (shallow area of only about 8” deep)

oi yoi yoi!
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,449
Laughlin, NV
Well. Not sure why you had that much more evaporation than we did.

Doing a CH test at very high ppm is not easy. Do you have a SpeedStir? Also, watch this Calcium Hardness Test Interference - YouTube

I also do not understand your high MA needs. I lower my TA to 70 when I fill the pool and then it stays there by letting the pH get to 7.6 or 7.8 and adding acid to drop it to 7.2. During the summer it takes the 8 oz twice a week and in the 'winter' it takes 8 oz about every other week. It is all driven by evaporation and adding the TA 130 ppm fill water.

When you want to drain I have an exchange method I use. Keeps you from letting your pool shell dry out. I have a fiberglass pool so prefer to not fully drain it unless I have to.
 

BigMouthStrikesAgain

Well-known member
Aug 30, 2017
50
Las Vegas
I ran a sample down to the pool store.
Here are the results:
FC: 4
TC: 4
SALT: 3500
CH: 1000 (he said it was higher but stopped at 1000)
CYA: 10
TA: 60
pH: 7.5
phosphates: 800
temp 80


the guy at the pool store said that I must have old water. I told him it is 9 months old. Then he suspected a leak. I am assuming if I had a leak, my CH would be much lower as it would be mixing a CH of 225 not 1000s.

As I look through my notebook here are some highlights:
JAN 2 - drained pool
JAN 3 - refilled pool. Cleaned SWG and filters. Fill water readings:
ph 8.0. fc 0. CH 225
then I started the process of adding chlorine (swg off for winter), CYA, and MA
FEB tests show CH varied btwn 250-300
MAR test show CH varied btwn 350-400
APR 1 Cleaned filters and installed SWG. Added salt over the next few days
APR 25 CH 500
APR 27 new SWG
JUN 2 cleaned filters and SWG. CH 700
AUG 7 small chip in plaster repaired. Noticed 3 months prior. Took a while to get them to repair it.
AUG 17 cleaned filters and SWG. CH 975.
SEP 9 CH 1075


it seems like a CH rise of about 100 per month
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,449
Laughlin, NV
Leak would show a lower CH.

Did you track CSI? The only reason I can see that your CH would increase that much would be some of it came from the plaster. Did you maintain a reasonable pH and TA all year? They would have had to been very low to dissolve calcium from the plaster.

Or you just had a lot more evaporation. I thought mine was high!

Anyway, you would be best to look at a drain/refill soon

Do you have a water softener for your home?
 

BigMouthStrikesAgain

Well-known member
Aug 30, 2017
50
Las Vegas
Hi, thanks for your quick replies.

I think it’s safe to rule out a leak as well. PH has been my main issue so I worked hard to maintain a pH btwn 7.2-7.8. TA was only checked several times.

We use a water softener for our home but as I understand, the fill water for the pool bypasses the softener.

Fill water PH 8.0. TA 140
FEB pH range 7.3-7.9 TA 60.
MAR pH range 7.5-8.0 TA 50-70
APR pH had several high readings. I was still working it all out but 8 of my readings are 8.0 and above! Range 7.4-8.6. TA 60
MAY pH range 7.4-8.2. No TA reading
JUN pH range 7.4-8.2. TA 70
JUL pH range 6.8-8.2 no TA
AUG pH range 7.2-8.2. TA 50
SEP pH range 7.5-8.2. TA 60
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,449
Laughlin, NV
It is best to track CSI here. If you are interested in an app tracking your data and doing calculations look at Pool Math. There is a yearly fee if you want to store your data.

If you have a water softener, I would suggest seeing if you can plumb it to your autofill. You would not use it for filling the pool initially, but for make up water.
 

BigMouthStrikesAgain

Well-known member
Aug 30, 2017
50
Las Vegas
latest numbers. I've added MA. and more MA... slowly starting to add CYA.
pH 7.5
FC 3.0
CC 0.0
TC 0.0
CH 1100
TA 50
CYA 45
Temp 86
CSI .01 (pool math says target is -.28)
I added more MA after this result. it should bring me to a pH of 7.2 and a CSI of -.26.

Does this CSI imply I can carry this excessive CH? I am wondering when to drain the pool. I believe I have about another month of the pool season. Then should I drain, refill, and remove the SWG? Or should wait out the winter and drain/refill in March when I open the pool?

Thanks!

- - - Updated - - -

Total Chlorine is 3.0 not 0.0
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,449
Laughlin, NV
Not sure what you mean by 'open' the pool. Your pool will be 'open' all winter. You will need to maintain FC, monitor pH, add bleach and acid as necessary, clean the pool, circulate it, etc.

No real need to remove the SWCG. Unless you want to and replace it with a dummy cell. I typically have mine off most of Dec and Jan.

You should plan a drain and refill this fall sometime. The CH of 1100 means it is time, soon.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
4,426
Central California
If you exhaust all the other possibilities and find that your pool still drinks acid like orange juice for breakfast, then with your IC40 you are all set for an IntellipH. I'll be happy to share my adventures with mine, if and when you're ready. Short version: LOVE IT. I haven't had to pour anything into my pool since installing it, and have gotten pretty lazy about testing, because my pool has been dead-on perfect the entire time. I was even able to leave it for almost a week this summer, without having anyone over to watch it. Luxury!

Oh, and I have another thread where I describe my adventures with the water softener. Shorter version: I no longer have any CH-rise issues...
 

Keddkilla

Silver Supporter
Oct 15, 2017
42
Las Vegas
I am in your same boat, so I will monitor this thread to see your outcome. I add about 36 oz. every 3 days for 25kish gallons. Does not matter what I do. I suspect my solar plays a part in it.
 

BigMouthStrikesAgain

Well-known member
Aug 30, 2017
50
Las Vegas
I’ve been keeping up with the pool religiously. This morning my pH was at 7.5 and FC at 3.0. I am slowly bringing up the CYA and I added some baking soda last week to get my TA up. My CH is still ridiculous. In the morning I added 8oz of MA in order to be good for a day. At 5pm I checked and my pH was at 7.2. I leave for a 3 day trip tonight so my wife will add 8oz per day of MA when I am gone.
I then checked the pH of my fill water. It is 7.9. I am wondering if the high pH water that is filling the pool is making me add high amounts of MA, and if so, does all of that acid make for a high CH? Or maybe the MA lowers my TA and a biproduct is high CH?

I am liking the idea of water softener water for my autofill. I will check the properties of my pool water vs fill water vs softened water when I am back in town. Also, would water softened by salt add to my pool’s salt content?

thanks
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,449
Laughlin, NV
CH is not created by adding MA. It is in your water source. Our water source is the Colorado River. It has a pH of about 7.9, CH of ~250 ppm, and TA of ~130 ppm.

The water softener will remove the calcium from the water. Sodium ions are exchanged for the calcium ions in the exchange. They are not NaCl, salt.

- - - Updated - - -

You should never have to add baking soda. I keep my TA at 60 ppm. The pH rises less fast with the lower TA. The acid I add keeps the TA under control as the fill water has the higher TA.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,449
Laughlin, NV
I still suggest you drain and refill to lower your CH. Then you can use softener water for make up to reduce your CH rise.