Startup SWG chlorinator salt for new pool

[Dirk]

i cant test CYA right now its overcast here not much sun.....all past tests have been strong sun, back to sun

This is why I abandoned the TFP method of CYA testing and standardized doing the test indoors under LED light. It's 100% repeatable, day or night, 365 days a year. I don't like to contradict TFP teachings, but their back-to-the-sun-rub-your-stomach-while-patting-your-head CYA test instructions just aren't for me.

You have to ignore the pool store CYA test. It's consistently one of their least accurate. It tells you nothing. Make no strategies based on the 62, it's meaningless. Trust your own CYA test results over theirs, any day. Try it indoors. Use these images as a guide (bottom of page):

Why Monitor Cyanuric Acid?

 

[Dirk]

PS. SLAMs can take weeks. Most finish much sooner, but you're not there yet, is all...

 

[FIESTA62]

SLAMs can take weeks

i understand but just getting concerned about the high level in my new pools surface, like it hit 40 but even at 35 i am thinking that's up there, but i realize CYA has a part in this to reduce the severity, its hard to hang in there when pool really is clean and i am bombing it constantly

 

[mgtfp]

If your CYA is much lower than you thought it was (not saying that I would trust the shop test, but as mentioned earlier, there are reasons why it could already be lower). And if that is the case, your high chlorine level would be quite underprotected from UV, and you would also have faster oxidation processes over night, resulting in higher overnight losses.

You could let FC come down to about 25ppm until the evening, and do an OCLT on that level. If you pass that, then good, keep the elevated level for another day and then slowly lower. If you fail that test, then you'll have new confidence that you're on the right track, but 25 should still be high enough to not go backwards in the SLAM, you'd just not go forward for a day.

 

[Dirk]

SLAM levels are safe for your pool. But SLAM levels are based on CYA. Retest your CYA. Any variance based on lighting is not going to make a significant difference.

Remember, once you mix the CYA reagent with the pool water, you can repeat the test as many times as you want to. Not by repeating the entire test with new reagent, just by pour the sample water back into the squirter, and then squirting it back into the testing vial. Do it outside a few times. Do it inside a few times, under different lights, etc. Average them all out to get a decent number.

It's not an unreasonable concern you have about blasting your new pool. But it's not a big worry either. Retest your CYA, confirm your target SLAM level, and don't go over it by overdosing.

 

[FIESTA62]

let FC come down to about 25ppm until the evening

ok that makes sense i will try that, but with my CYA testing you might remember i messed around for ages getting it right, or right to what i think is a standard test, i test only on the bright sunny days, back to sun so test is in my shadow, hold waist level, and glance not stare etc, i did this a few times to confirm and got the extremely faint almost hard to see at 80, but defiantly gone at 90, depending on eyesight many would say 80

having said this this test seems still pretty subjective a bit more light and i see dot, bit less light and no dot, i did try under led light in the early stages and might retry that again, as if i can standard that method then its always going to be the same, as Dirk suggested

 

[Dirk]

The other reason to be careful not to overdose, is that it's skewing your calculation of actual FC loss. Right now you're losing FC in three ways:
1. algae
2. normal loss to UV
3. overdosing beyond what your CYA can support.

You can eliminate #3 by not overdosing.
You can eliminate #2 when you test and dose and retest at night.

That leaves you with actual FC loss due to the algae.

 

[FIESTA62]

sense to confirm your CYA again

ok will test not much sun but i will give it a go and buffer etc

 

[Dirk]

If your CYA is much lower than you thought it was (not saying that I would trust the shop test, but as mentioned earlier, there are reasons why it could already be lower). And if that is the case, your high chlorine level would be quite underprotected from UV, and you would also have faster oxidation processes over night, resulting in higher overnight losses.

You could let FC come down to about 25ppm until the evening, and do an OCLT on that level. If you pass that, then good, keep the elevated level for another day and then slowly lower. If you fail that test, then you'll have new confidence that you're on the right track, but 25 should still be high enough to not go backwards in the SLAM, you'd just not go forward for a day.

I'm not crazy about this idea. I think it would be better to confirm the CYA level, testing as I described in post #365, and confirm or reestablish your SLAM level target for FC. Then stick with that until nighttime testing (or an OCLT) confirms the algae is gone. In other words, stick to the SLAM directions...

 

[Dirk]

If you see any amount of dot at 80, however faint, but none at 90, your CYA is 90 for the purpose of the SLAM. You round up to the nearest "10" for the CYA result.

 

[FIESTA62]

ok as i need to add buffer to test cya, is it one of the regents from the TA test?, 0007 or 0008 or 0009.......the only regent that i have that actually says "Buffer" is the Calcium buffer

 

[mgtfp]

I'm not crazy about this idea. I think it would be better to confirm the CYA level, testing as I described in post #365, and confirm or reestablish your SLAM level target for FC. Then stick with that until nighttime testing (or an OCLT) confirms the algae is gone. In other words, stick to the SLAM directions...

Thought you'd say that. I probably would have replied the same way had you suggested my suggestion

Confirming CYA is certainly the best option, but I know how little I trust that CYA test when the light is not right.

But I see some benefit in a confidence booster.

 

[mgtfp]

ok as i need to add buffer to test cya, is it one of the regents from the TA test?, 0007 or 0008 or 0009.......the only regent that i have that actually says "Buffer" is the Calcium buffer

In the CCL kit it's called Total Alkalinity Buffer, with a 2 on the bottle. In Taylor notation it is R-0007

 

[FIESTA62]

confidence

yep need that...starting to waver....

 

[FIESTA62]

R-0007

ok great i am using taylor kit, but restock regents with CCL now....ok R0007 i will go and test now

 

[FIESTA62]

ok tested cya, i use the taylor bottle 7ml pool water, then 1 drop of 0007, then top up to 14ml, gave good shake, tested in reasonable sunlight got 40, did it 4 times get 40
ok i thought put another drop of buffer in so 2 drops now, retest same thing 40, came inside checked in kitchen under led lights 40

same testing method i did weeks ago and i got 90 but that was before slam and before backwash, lost a fair bit of water then and topped up, we did have week of rain a few weeks ago too etc

but 40 seems too far from 90, but not too far from pool shops 62, but really i tested really carefully i know how subjective it can be so i am all over it, but 90 now 40 ? is it because of the high chlorine putting test off ?

 

[FIESTA62]

just to say, i have clear choice regents and there test tube too, i can retest using there gear, but would assume Taylor kit would be fine....

 

[Dirk]

Well, a CYA of 40 would explain the massive FC losses you're still having. As long as you're using Taylor reagent with Taylor test vial (or CC with CC), then you're good.

Still sticking with my advice. You now have a valid CYA number. Your SLAM FC level is 16. Use that for a day and a night and see if your FC losses go away. My guess at this point is that you're done with your SLAM. Run it another day/night to confirm.

 

[Dirk]

By the way, you can see now what I meant by the lighting for the CYA test not being that critical. You now know you can test indoors and get the same result as outdoors. Let go of this notion that you can only test CYA when the sun is out, when the moon is in the Seventh House or when Jupiter aligns with Mars. Just test it in the kitchen under the same light from now on and stop planning around the sunlight.

It's been said here over and over: and confirmed by our experts, over and over: Using consistent, repeatable test methods is far more important than getting the number exactly right. That might sound contradictory, but the fact is pool water maintenance has more to do with trends than true values.

Examples:

My pool got a tinge of algae when FC dropped below 3. It doesn't matter if the FC was actually 3, or 2 or 4. As long as I test FC the same way every time, I know my pool will get algae if my FC testing method result is less than my 3.

Same for CYA. After a few years, I know my FC holds just fine if my CYA is between 70 and 80. It doesn't matter if my CYA is actually 70 or 80. It doesn't matter if my indoor CYA testing method is off by 10 or 20, plus or minus. Because I've standardized my CYA testing method to an indoor LED light, I can reproduce my CYA testing method whenever I need to, morning, noon, night, winter, summer. If I get 70-80, I know I'm good. The fact that those numbers also match TFP guidelines is great, but it doesn't ultimately matter. My 70-80, however I come by it, works in my pool. And that's what matters.

 

[FIESTA62]

done with your SLAM.

yep thats what i think its too clear to be needing slam, but whatever.....but why from 90 to 40 thats a huge drop does slam make cya less or is high chlorine messing with the test....
strange i was so careful adding CYA trying not to overshoot. i bought all from local Bunnings hardware chain, every time i added i did not see much of a increase, seemed to be around 40 or 50 , then i bought a bit more expensive brand from pool shop and bam 90, i realize its probably all the same , but coincidence the brand name seemed to work