First Chemistry Test

[russ0486]

Just replaced equipment for an existing pool and installed a SWG. Haven't added salt to pool water yet.

Got my TF-Pro-Salt test kit in the mail today and did my first test. Results are:

pH 7.2
CH 650 ppm
TA 40
CYA <30 (see note below)
FC 7.5
Salt 1000 ppm

I added test solution to the CYA viewer tube and the black dot was barely visible at the 30 mark (top of the viewing tube). Therefore, I'd say CYA is slightly less than 30.

I was surprised to see salt at 1000 ppm, considering I just installed the SWG and hadn't added any salt to the water. Could this be a bad result or is it likely that salt was 1000 ppm?

I know I need to do the following (in no particular order):
Get salt to 3600 ppm (per IC40 recommended level)
raise CYA to 70-80
raise TA to 60-80

Any particular order to do this in? Any other changes I should make before/during this first round of adjustments?

Thanks in advance.

 

[proavia]

No real particular order.

Raise TA to 60-70, no higher to limit pH rise once TA is increased.

Add CYA from 30 to 60 for now. You can always raide it higher at a later date.

Add salt to attain a salt reading of 3000 ppm. While 3600 ppm may be the optimum the manufacturer recomkemds, most will work in the 3200-ish range. Sneak up on the 3200-ish. If you ofershoot, you will need to exchange water to get the level down.

The 1000 ppm salt is probably correct. Chlorine and acid use will add salt to the pool water and your fill water may have a bit of salt in it as well.

 

[Newdude]

*never raise CYA significantly without an
Overnight Chlorine Loss Test.

SLAM FC is 12 at 30 CYA, and 28 at 70 CYA. You realllllllly want to know there's no algae before you make it way more expensive to kill.

 

[pjt]

TA 40

Did you keep adding drops until there was no further color change? It typically takes another drop or two after the initial color change. If your TA is truly 40, add just a whisper of baking soda to get your TA to 50-60. What's the TA and CH of your fill water?

 

[russ0486]

@Newdude good info - I did an overnight test as you suggested and I did not "lose" any chlorine. Worthwhile to double check though so thanks.

@pjt yes, I added drops until no further color change. And I retested water and TA came out to 30 this time so I'm fairly confident it's in that range.

Fill water tested at 70 TA and 125 CH.

@proavia good advice - I will creep up on salt, CYA, and TA levels to make sure I don't overshoot. I've bought the chemicals recommended from this page: Recommended Pool Chemicals
Planning on adding some later today, retesting tomorrow, and then making fine-tune adjustments from there.

Thanks again to all for input. Very helpful.

 

[pjt]

And I retested water and TA came out to 30 this time so I'm fairly confident it's in that range.

Add enough baking soda to achieve a TA of 50. Do you know how your TA got so low (MA, trichlor, etc.)?

Fill water tested at 70 TA and 125 CH.

Just be aware that every time you add fill water, you're increasing your TA and CH, especially since your CH is 650. Do you know how your CH got that high? Try to harvest as much rainwater as possible.

 

[russ0486]

Do you know how your CH got that high?

The short answer is no, not really.

The long answer is:
We bought this house last summer and the pool was a mess. It had a large leak, which we've since fixed. But we suspected that previous owners (or their pool guy) was adding quite a bit of water on a weekly basis just to keep it full. Chemistry was therefore out of whack. Equipment was worn out. We are doing a full remodel of house so after we fixed leak, we put pool on back burner until we recently replaced equipment and now starting to bring it back to life. We will need to replaster at some point in near future, but trying to push that off for a year or two due to other expenses. So in short, I suspect TA and CH levels are due to constant refilling and lack of attention.