Drain Pool after two seasons due to high CH?

[QingGuy]

My numbers per my Taylor test kit are as follows:

FC - 6
CC - 0
pH - 7.7
TA - 80
CH - 700-750 (I input 725 in pool math)
CYA - 50
Salt - 3,800
CSI - -.17
TDS (per pool store) - 500​

Per our water district CH from the tap is 300. When I tested with my test kit I get 250, however, I always have a difficult time testing CH and knowing when it really changes color, thus my range of 700-750 above.

So, based on these numbers do the experts recommend I drain? Water is about 31-32 months old. Could my CH really rise to that level in 31-32 months? Oh, one more note, this is a new build so this is the first batch of water the pool has seen.

 

[pooldv]

There are some more detailed test instructions for CH here, Pool School - Extended Test Kit Directions

It is not necessary to drain to lower your CH ... yet. We have quite a few folks in the southwest who manage their pools with CH in the 1000-1200 ppm range. What is important to do when trying to manage your water chemistry when one or more parameters are outside of TFP recommended levels is to manage your CSI. Keep your CSI between -0.3 and 0 to prevent scaling. Poolmath will give you your CSI number after you input your test results. Adjust your PH and TA to move your CSI around.

More here, Pool School - Calcium Scaling

Also, people have been successful slowing their pH rise by diverting gutters rainwater to the pool. Rainwater is CH free water for free.

 

[Texas Splash]

^^ I agree ...... no drain. Your CSI is still within acceptable ranges and will continue to be that way for quite some time as long as you consistently monitor TA and pH to ensure they do not climb too high. That's key. Beyond that, we know CH will not drop unless you exchange water which may difficult there for you since consistent rain is not an option. Some folks chose to augment daily water refills with softened water to help slow-down the climbing CH level, but not everyone has that ability. But for now, if your CH test is actually 700-ish, it is still manageable via TA & pH.

I understand how the CH test can be tricky. I have that issue at times. Hopefully you have a speedstir which can make a tremendous difference in that test. But take your time, and watch that solution change carefully from red to blue. It's not a dark blue which can make the change difficult to catch, but make note of the color change and record. If you add another drop or two and see no further change, then just stick with your first note of color change. Hope that helps.

 

[QingGuy]

Thanks for the input. I tend to run on the high end of pH, I'll have to keep a closer eye on it, TA too. pH will usually get up to 7.9/8 and then I'll add some MA to bring it down. TA up to 90 then I'll bring it down to 60/70 range. Knowing that my CH is so high I'll watch it more closely testing every other day rather twice a week.

I don't have a SpeedStir, I'll have to pick one up and take notes on the CH test. As I said, water company claims CH is 300, when I do my test I get 250. Got to get better at doing that test.

Unfortunately not a lot of rain here in Las Vegas. In-fact I think the state of Nevada ranks last for annual rainfall out of all the states.

So consensus is don't drain at current CH. For future reference, what level should I consider draining at?

 

[Texas Splash]

Others in your geographical area have CH levels ~ 1,000. So for now, with close testing and management of TA & pH, your CSI should be fine for a while. Definitely try to get the speedstir though. It makes a difference. I wouldn't worry about draining until pH and TA no longer have a positive effect on managing your CSI.

 

[pooldv]

Try lowering your TA to 50, that will help to slow pH rise.

 

[QingGuy]

My SpinStir arrived and I think I have a much better read on my CH. Using the 10 ml test my water turned purple around 800 (32 drops) and blue at 1050 (42 drops). Here are my updated numbers:

FC - 4
CC - 0
pH - 7.4
TA - 70
CH - 1050
CYA - 40
Salt - 3,800
CSI - -.27
TDS (per pool store) - 500​

So with my new updated numbers is the consensus still to not drain?

I did attempt to bring down my TA, poured in gallon oz of MA and it only brought it down to 70. I suppose I'll try again this weekend.

 

[triptyx]

Ignore TDS for now. It's not a very useful number.

When you calculated CSI, had you put in an accurate water temperature?

 

[QingGuy]

Ignore TDS for now. It's not a very useful number.

When you calculated CSI, had you put in an accurate water temperature?

Yep, a chilly 46 degrees

 

[JoyfulNoise]

My CH is currently at 1000ppm...no visible scale at all just evaporite from a splashy spa spillover (that happens no matter what the CH is). I just noticed the other day the slightest bathtub ring on the tiles. A little muriatic acid on a sponge will take care of it.

You're fine....

 

[QingGuy]

Now that I have a better feel for my CH I'm a little worried about my water last year. I ran some numbers and I'm thinking worst case my CSI may have gotten as high as .60 for short periods of time during the warmer months last year. Now the CH probably wasn't quite as high as it is today as that was several months ago but I'd say it easily hit .5 at times.

Think I have any thing to worry about?

 

[pooldv]

Not if you don't see any scale. It normally shows up on the waterline tile first.

 

[QingGuy]

Thanks.

What's crazy is I have neighbors who have done 5+ years without draining, have pool guy who basically throws pucks in their pools and no issues with their pools. They would have no idea what CSI is, and I'm freaking out that my CSI may have hit .50 LOL.




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[Rollercoastr]

Thanks.

What's crazy is I have neighbors who have done 5+ years without draining, have pool guy who basically throws pucks in their pools and no issues with their pools. They would have no idea what CSI is, and I'm freaking out that my CSI may have hit .50 LOL.

TFP syndrome. Other symptoms include scorn of pool store products and a reluctance or refusal to swim in other pools.

 

[pooldv]

Thanks.

What's crazy is I have neighbors who have done 5+ years without draining, have pool guy who basically throws pucks in their pools and no issues with their pools. They would have no idea what CSI is, and I'm freaking out that my CSI may have hit .50 LOL.




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Trichlor pucks are acidic and slowly lower pH and TA over time often leading to having TA crash and pH drop to ridiculously low levels, like 2-4, causing all sorts of damage to plaster, heaters and other pool equipment. Nevermind the endlessly rising CYA and issues with that. They are on a tightrope that could come down at any moment and they are often just lucky with rain and enough TA in the fill water to keep it from happening for a while.

 

[Reddogdan]

I'm curious as to your adding MA to lower your TA. I thought MA only lowers PH.

 

[pooldv]

In PoolMath there is a section called Effects of Adding Chemicals, if you select muriatic acid it will show you how it will impact pH and TA.

 

[proavia]

I might be inclined to doing the CH test again. I always got a higher CH when NOT using my SpeedStir do to inconsistent manual swirling.

Are you holding the reagent bottle completely vertical, letting each drop fully form on the tip, waiting about 1 second between drops? I was able to consistently get a reading 150 points lower using that method.

Right now, my CH is at 925 and I manage my CSI to be slightly negative. No scale and no waterline deposit.

 

[jontomosicz]

In Phoenix, we have the same problem of high CH fill water and little rain. So our CH level is steadily rising. My PB recommends partially draining the pool every off season by 1/3 to keep the CH level in check. I'm curious...what's everyone's thoughts about that method?

 

[QingGuy]

I might be inclined to doing the CH test again. I always got a higher CH when NOT using my SpeedStir do to inconsistent manual swirling.

Are you holding the reagent bottle completely vertical, letting each drop fully form on the tip, waiting about 1 second between drops? I was able to consistently get a reading 150 points lower using that method.

Right now, my CH is at 925 and I manage my CSI to be slightly negative. No scale and no waterline deposit.

Early in my addition process I'm what I would call rapid firing the drops as I know I'm going to be at least 25+ drops in before the color starts changing. This may have resulted in less reagent per drop. towards the end I'm definietly doing slow drops. Also holding vertically. About 1 second between later drops as well.

I'll test again going slowly.

I see no build-up on my waterline.