Trouble reading pH and CYA

[rd783]

Attached 2 photos of pH test, 1 inside light and 1 outside light. Hard time determining, is it around 7.9/8.0?



Also attached photos of CYA filled to 50, 40 (barelyy visible?), and 35 (pretty sure can't see it anymore)
What’s my CYA?


(By the way last week my CYA I could easily see in the test at the 30 line so I then added 3lbs of stabilizer - so did my CYA really only go up 5ppm?)

 

[PoolStored]

7.9 and 50

It should look like your 50 sample looks in the picture. However, you should do the test outdoors, sun at your back, hold tube at your waist and take a GLANCE. If it looks like your 50 sample, that's when you are done. Round up to next 10. If it was at the 50 line when it looks like your 50 picture, your CYA is 60.

 

[rd783]

Well if it's 50/60 would this make sense? (all tests also had 0 CC)

Yesterday 8:14pm 4.0 FC

Today 6:50am 4.0 FC
+60oz of LC (raise FC by 3ppm)

Today 12:14pm 3.5 FC -- it's like my 60z did nothing?

Today 7:23pm 3.5 FC
+72oz of LC (raise FC by 3.5ppm)

 

[PoolStored]

No, it is likely you have algae (yes, even if you can't see it.) or testing error.

Do this test tonight...Link-->Overnight Chlorine Loss Test

How are you chlorinating? Do you have SWCG? If yes, what the is cell brand and model, pump runtime and cell output%

How old is your chlorine? Post the date code.

How old are your reagents?

 

[rd783]

Plaster Pool is only 3 weeks old so liquid chlorine, will add salt after 30 days and turn on SWG

Just bought the 10% chlorine from Walmart and the test kit is brand new

 

[PoolStored]

To the OCLT.

 

[mknauss]

Follow the start up procedure for your plaster. Be careful using FC higher than 3 ppm for the first 30 days.

 

[rd783]

What’s OCLT?

I was never given any startup procedure
Was just told no salt for 30 days and no vacuum for 14 days and for the first 2 weeks I brushed 2x a day now doing 1x a day

 

[Pool Amateur]

Do not mean to disagree with PoolStored as I have read previous posts of his and he is quite knowledgeable about pools, But I would think that the results are 35 ppm for CYA if pic 7002 is the 35 ppm test, I see the dot way too well in 6999 and still too visible in 7001 for me. Also, when you add CYA it may take a week for it to read the correct level. So it may be more than 35 depending on when you added it vs the time of the test. From old PoolMath page you need 4 LBS of stabilizer to bring 16k pool from 0 ppm to 30 ppm. The fact that you could see dot clearly at 30 ppm level a week ago indicates there was less than thirty but does not tell us whether it was 5 or 10 or even 20. So 3 lbs. could easily yield a reading of 35 ppm. But if a week has not passed from addition to test it could be slightly more. By the way, how did you determine 35 ppm for pic. the tube in TFP kit uses 10 ppm increments and the results are not linear, so if it was half way between 30 and 40, round up to 40 as PoolStored said above. Am I making a mistake here? Marty and PoolStored let me know.

 

[Pool Amateur]

PS to my last post, if this is new pool, and CYA had never been introduced to the pool before your 3 lb. addition I would think the reading would have been below 30 ppm. This will cause FC to burn off fairly quickly and would be a good reason why you thought your 60 oz. did not do much over a 4 hr. period of sun. Also, I have a vinyl pool so I do not know much about plaster, Marty why the restriction of FC to 3 ppm over the first 30 days? Also how do you clean a pool or keep it clean at 3 ppm especially if you have 40 or 50 ppms of CYA?

 

[rd783]

I should have been more clear
6999 - fill line is at the 50
7001 - fill line is at the 40
7002 - fill line is halfway between 30 and 40
(I have now renamed the photos for clarity)

The pool company did maybe 2 included initial visits, at 1 point they added 1 gallon of acid and they were throwing tabs in the skimmer - no idea if they added any CYA. (Then thankfully I found this forum )

Anyway, before May 31 I had the CYA tube filled to the 30 line and could see the dot easily.
May 31st I added 3lbs of stabilizer via the sock method, so it's only been 4 days to today.

According to TFP I want CYA of 60 for SWG, so my thought was in preparation of adding salt later this month I should slowly start raising CYA to 60

Also on this page

CYA - Cyanuric Acid Test

Cyanuric acid (CYA) is the chemical name for the product commonly called “pool water stabilizer” … Read more…

www.troublefreepool.com

6. Continue pouring until all traces of the black dot at the bottom of the view tube completely disappear, even after you stare at it for several seconds, or you fill the view tube.

and this page

CYA Testing - Further Reading

www.troublefreepool.com

• Don't stare at the dot as you pour
• Fill to a line, hold the tube waist high, and glance at the dot
• If you see the dot fill to the next line and glance at the dot

So do I "stare" at it or "glance" at it?

thank you guys for your help!

 

[Pool Amateur]

I tend to stare on a sunny day with my back to sun holding tube with 2 fingers at waist level. I think the problem with staring is that even with back to sun there is a glare that can resemble the dot, but in reality the "dot" has disappeared. if it looks like your 7002 pic that is what I look for. Still will look forward to Marty's "mknauss" response on why not over an FC level of 3 ppm on new plaster pool for 30 days. If you use minimal CYA (30 ppm is what I would consider minimal) you would be able to maybe manage the pool till your 30 day mark. It will however use more chlorine faster. Again look forward to Marty's comments. But will prevent you from slamming till 30 day mark.

 

[PoolStored]

7002 - fill line is halfway between 30 and 40

^^^The way it was described, I took first photo to be 50.

This is the correct "what it looks like"...7002. Your CYA is 40 (round up)

 

[mknauss]

If you have no guidance on start up, you should at least try to follow https://www.nptpool.com/pdf/npc-start-up-card-lsi.pdf
You should keep the FC low as possible as there may be organic dye in the plaster and you do not want to bleach that before it is fully cured.
You may have to add chlorine multiple times each day to achieve that.

From your pictures, CYA is at least 40 (round up). The tablets the pool builder added raised CYA.

 

[Pool Amateur]

Thanks Marty, Just another question that brings to mind, does that "3 ppm" apply for all levels of CYA or can you go higher with higher levels of CYA and not have the strong bleaching or oxidation level as say 3 ppm with no CYA? I do not have plaster but I often here people remark that with the 50 ppm level of CYA a FC of 5ppm is not as oxidative as 1 ppm with no CYA.

 

[mknauss]

Your CYA level should not be above 50 ppm (and preferably 30 ppm) for initial curing of plaster.

 

[rd783]

"initial curing of plaster" - you mean first 30 days? I will leave CYA alone going forward for now hope I didnt screw anything up

 

[mknauss]

As per the NPC, the first 28 days are the 'curing' period.

 

[Pool Amateur]

RD783,
My personal opinion, if you put the CYA in using sock in front of return when the sock is empty the CYA level reads pretty much accurate within a day or so but it is possible some of the CYA is undissolved in the filter for a few more days. But I think calling your CYA level at 40 is accurate. That being said I would also not exceed 3 ppm till the 30 day mark unless I found info that higher level of FC with higher level of CYA would not damage the plaster. This may mean I start to get some green but I would live with it vs risk bleaching out the stain in my plaster, At 30 day point (which you are close to) I would add salt to bring to level your unit recommends (mine is 3500 ppm) if you pour it in 1 place in a pile then push it around it dissolves quickly within minutes. I would also at that point SLAM the pool at the 40 ppm level (takes less chlorine and less DPD reagent and is faster in my experience than SLAM at 60 ppm) till I passed the OCLT. Then I would turn on SWG and put in the remaining amount of CYA using sock method in front of return. From what I understand it does not damage the SWG to run at lower levels of CYA but requires it to produce more chlorine because sun burns it up faster and it will only be for a short time and you will be dialing it in anyway. Also SWGs are not "set it & forget it" as sometimes advertised. As days get hotter longer and very sunny more chlorine is used and therefore either more run time or higher output needed from SWG. Have a big party, run SWG a little longer that day. Again test kit will be your guide. Once you get the hang of it, it is easy and do things instinctively.

 

[rd783]

Thanks for all the helpful info guys, will test 2/3x a day and try to keep CL around 3/3.5ppm while I finish out the first 30 days.

By the way attaching another pH reading - would this be 8.0?