CH(Calcium Hardness) keeps creeping up over 400

Neoex

Active member
Jun 18, 2019
38
Tulsa
My pool is approx 1 year old, details in my sig. The calcium hardness from the tap is 150, but about every 2 weeks my hardness is going up about 15 points. Once it gets up to 450, I have been draining about 30% of my water and refilling and it brings it back down to about 300 and then it starts going up again.. The pool store(Leslie's) says most people have to actively try to raise their hardness and I am the only pool with this issue that they have seen. I have checked my SWG and it doesnt look like it has build up in it.

What could be causing this?

EDIT: I am getting white flakes in my pool when i wakeup they are around the bubblers, my PB says they are "Calcium flakes" but i dont understand where they could keep coming from. I have replaced filter my and the issue persists. I was having to use heavy amounts of noPHOS to get my phosphates down (were up to 3000+). Could the noPHOS be doing it?
 
Last edited:

scottts

Gold Supporter
Nov 13, 2019
139
Gilbert, AZ
Are you using any calcium-based chlorine? Cal-hypo shock? Do you use any sort of evaporative cooling on your pool? When water evaporates it leaves any calcium and other minerals behind to build up.

Also, how do you maintain your pools ph? If ph is too low you could leach calcium from your gunite.

Do you have your own test kit?
 

Neoex

Active member
Jun 18, 2019
38
Tulsa
I use my intelliPH to inject acid generally my PH is on the hide side 7.8-8.0.

i am using DryTec Calcium Hypochlorite Granular
Calcium Hypochlortite 68% to shock the pool

My last stats were
PH 7.6
ALK 90
FAC 4.7
TAC 7.5
PO(Phosphates) 174
MT .3
CYA 36
CH 391
Salt 3100

I do the testing myself but I go once a week to leslie's and have them run it to "verify"
 

wilkj1

Gold Supporter
Bronze Supporter
Nov 27, 2017
175
okc/okla
there is your calcium go to Liquid chlorine only and is your heater on it and your SWG can cause flakes how are you testing ? what kit?
 

CrystalRiver

Well-known member
Jun 19, 2020
235
Massachusetts
You are adding calcium to your pool. That is why the calcium is going up. The only ways calcium can leave is by draining/splashout. Evaporation leaves the calcium behind.

You can switch to dichlor or trichlor, but then you'll have the same problem with CYA instead of calcium. Or you can switch to liquid chlorine, which doesn't have those kinds of side effects.

Are you "shocking" your pool regularly? No need unless you have a problem, and if you keep your numbers in line, you will never have a problem. Stay out of pool stores. Get your own test kit and ignore anything they tell you. Leave your phosphates alone, too. Phosphates are algae fertilizer, but that doesn't matter if you keep your chlorine where it belongs, because algae cannot survive with adequate chlorination, no matter how much fertilizer you give it.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
34,300
Sebring, Florida
You are being pool-stored. The Calcium Hypochlorite is adding the Calcium to your pool.....stop using it... for anything. You CH will stop climbing.

Use Liquid chlorine to sanitize your pool and start learning how to perhaps never shock your pool.....certainly not with Cal Hypo.

Please read "The "ABC's of Pool Water Chemistry" up in Pool School. That is our basic guide and will get you started on what we teach.

The phosphate remover is adding money to the pockets of the pool store and that's about it. It's a different subject so focus on how and why you will stop using Cal Hypo first.

It will require some reading and some learning (and buying a good test kit) but your pool will look like many you see on this forum.
 

wilkj1

Gold Supporter
Bronze Supporter
Nov 27, 2017
175
okc/okla
I havent been using my heater for the summer however the water does go through it, do you have an example liquid chlorine, amazon link? tf-100

EDIT: something like this?

lowes/ home depot have 10% LQ for like 4 bucks a gallon.....$7.48 for this at lowes

Kem-Tek 256-Gallon Liquid Pool Chlorine
$7.48

183
Kem-Tek 256-Gallon Liquid Pool Chlorine
 

jimbethesda

Gold Supporter
Jul 2, 2018
440
Austin, TX
With an IC40 and a 9,000 gallon pool, you shouldn’t ever need to add any chlorine to your pool. You’ll only need liquid chlorine if you don’t follow this chart and get algae.

 
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Neoex

Active member
Jun 18, 2019
38
Tulsa
I have my IC40 set to 25% and after a hard day of usage I usually do the Superchlorinate function inside my app. Does this sound about right?
 

PoolBrews

Well-known member
Oct 16, 2019
230
The Villages, Florida
One point I don't see addressed here is that you don't need to drain and fill when it hits 450. As long as all of your other numbers look good, you can let CH go pretty high before draining and filling.

My tap water is also 150. My CH goes up by about 25 every 4-6 weeks - due to evaporation and fill. Once my CH gets up in that 600-750 range, I do a water transfer and bring it back down to 350. I have to do this about once a year.

The first step is to get your current CH rise under control, and you now have all the advice you need to do that. The 2nd is to realize you can let it go a little higher than you have been as long as all your other numbers are good.
 

jimbethesda

Gold Supporter
Jul 2, 2018
440
Austin, TX
I have my IC40 set to 25% and after a hard day of usage I usually do the Superchlorinate function inside my app. Does this sound about right?
How long does the pump run for? That’s the other variable needed to answer your question.

Also, your testing will tell you if that’s enough. Why were you “shocking” your pool?
 

Neoex

Active member
Jun 18, 2019
38
Tulsa
So let me backup a bit, after they did the plaster (Pebblefina) they told me be religious about brushing it as it will produce like a white material from the plaster while it cures, and I did, I brushed the thing like 10 times a day but the white stuff was STUCK, it would not come out especially in corners or edges that you couldnt get the brush too. So after 2 months, they drained my pool and acid washed it, everything was perfect. My pebblefina is seeming to show some calcium build up AGAIN, thats what my PB thinks, its sporadic and "marbled" for lack of better term in certain parts of the pool, its white in color. He said it maybe calcium build up so thats when we started paying attention to the CH.

Here are some pictures of how it looks
image0.jpeg
image1.jpegimage0.jpegimage1.jpeg
You can see the left side of the pool doesnt seem to show any of this coloring but the right side does?! no clue what the ****


my pump runs 20 hours a day 11am-7am, shrug thats how my PB set it up, after adding the glacier chiller I do need to keep it running at night if i want to leverage the cooling
 

jimbethesda

Gold Supporter
Jul 2, 2018
440
Austin, TX
You are generating 3.9 PPM of chlorine every day. That does seem “about right” as you say, but you really need to get a good test kit and measure it yourself, making sure you follow this chart. As far as the plaster goes, I’ll defer to others. Not adding cal-hypo regularly will for sure help keep your calcium level in check.

To summarize. Get a test kit (TF-100 or Taylor 2006c), download the Pool Math on your phone and keep your CSI in the target zone.

 

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