Troubled Owner, New Member from Sydney, Australia

[Pavle]

How did the pH get that low? Your PoolMath logs shows a TA of 75 (that would be 80 as you cannot measure a 75 with a drop based kit). Very hard to have a low pH with higher TA. A little aeration will drive the pH up quickly.

I don't know how or why PH is that low, apart from liquid chlorine and topping up with fresh water (evaporation and back flush), there has been nothing else added to the water. I was expecting it to be super high, not low.

My Clear Choice TA test says One drop at a time, add the total alkalinity titrating reagent. Mix between each drop, and count the total number of drops added until the colour changes (usually to red, but possibly also pink, yellow, or clear). If you are unsure whether the colour change is complete, add one more drop – if there are no more changes, don’t count the extra drop in your total. Multiply the number of drops by 25 to get your TA level in parts per million (ppm).

I added 3 drops multiplied by 25 = 75

 

[mknauss]

With the TA, you are better off to use a 25ml sample. Then each drop to red is 10 ppm.

 

[Pavle]

Thanks, I will give that a go.

 

[Pavle]

Full test results after another full day:
(should I open a thread in water chemistry discussion now)?

CYA: 30
FC: 9.5
CC: 0.5
PH: 7.4
TA: 40
CH: 870
Temp: 25 deg C
CSI: -0.18

What is advised from here?

 

[mknauss]

No need to open a new thread - best to keep discussion here.

I see no reason to adjust anything. Your TA is low ( I assume testing improved with the larger water sample) but if the pH remains stable I would not bother with it. Your CSI is good with your high CH. As you cannot do a large water exchange you will need to manage pH and TA to keep your CSI in its current range. Follow the FC/CYA Levels for FC. I question your automated LC system will keep up but that is up to you to manage.

 

[Pavle]

I’ve bypassed the automated system for now and turned it off.

TA was tested at the larger water quantity, yes.

 

[AUSpool]

G’day Pavle,
I’m defiantly in the SWG camp and would never be without one but I think you can continue to use your Stenner pump, just disable the ORP function and use it on a simple timer. Tune it in to your required dose by adjusting the run time which is pretty much what the average SWG does.

What is your salt level? Both acid (HCL) and bleach add salt to the pool which will buildup over time. I would think you’d be somewhere around 500-1000ppm. You should be using that in the test logs to produce your CSI

 

[Pavle]

G'day Steve,

I don't actually have a SWG, I've got a Rola Chem RC9 and it's not possible to run it without using the ORP function.
The device takes PH and ORP measurements then calculates how long it needs to continue to dose either liquid chlorine or MA.

If things remain on the right path and I can keep my water on track, I will try and offload that unit and pick up a couple of Stenner pumps and rig up my own automated unit.

I don't have a salt test kit.

 

[AUSpool]

I knew you used bleach with a peristaltic pump, I was just saying I’m a fan of the SWG. I was thinking you might be able to turn you ORP value to the minimum so that it always wanted to dose and run it in the timer mode.

Salt is a proxi for TDS in the CSI calculations. Town water will have salt in it to start with and then the acid and bleach will also add salt. If your CH is high your salt may be high to. However salt will not affect the CSI value until it goes over 1000ppm. CSI will decrease as the salt value increases. Given your latest numbers if your salt value was 1100ppm your CSI would be -0.19, at 1500ppm it would be -0.22, so not a big change but maybe nice to know.

It may be worth noting too that when this summer turns to winter and your temp drops your water will become aggressive, you will want to let your pH or TA creep up to keep you CSI as close as you can to 0.0.

 

[Pavle]

We have had a heap of rain the past 3 days and I’ve had a chance to get a bit of water out and allow the rain to top it up. Ran the numbers tonight and has hardly made any impact to my CH, but it’s heading in the right direction.

everything else is going well, FC is in maintain range now and apart from not a lot of sun, pool looks very inviting again!

Thanks for all the guidance