Initial THANK YOU and advice on CYA

[cbredesen]

Hello forum. First, let me say THANK YOU to all of you for this awesome repository of knowledge. In the few days I've been reading posts as well as perusing the Pool School, I have learned more than the cumulative 3 years I've been maintaining my pool. Also, local pool stores are frustratingly inadequate for those of us wanting to learn, not just react. So again, thanks.

I'll try to be concise by saying that I have a CYA problem. I didn't know I had this problem until my local pool store finally told me that it was off the charts. Never mind the years before that during which they and 2 other shops never said a thing. Nor did they see anything wrong with endlessly feeding trichlor tabs into my 10Kgal pool without ever replacing water (I have a cartridge filter and never have occasion to remove water).

I couldn't keep chlorine in it and they took a guess at my CYA level being 300 (!!). So I drained the water, twice, and shocked and adjusted. Things were OK. That was a couple months ago. Now again this summer I'd been getting algae blooms at what I consider normal chlorine levels (4-5ppm) and even superchlorinating to 10 wasn't fixing algae or cloudiness. I'd get answers like "put a whole jug in and wait 24hours" etc. Maybe that was right, maybe not. But I finally searched and wound up here. The key of course is my CYA level and the fact that with 100ppm of CYA, 10ppm of chlorine doesn't do squat

So I drained half again, for the third time. They'd told me my CYA was 100 and thus replacing half the water would get me to 50 and using the chart, I began my SLAM with a shock to 20ppm. First night I lost 3ppm so I kept it at 20 the next day. Second night I lost <1ppm so I'm happy. I'm letting the chlorine level come down and the pool looks much better than it has in months. It's starting to sparkle again.

Today my full test kit arrived and I decided to test the CYA levels for the first time. First run, I was nowhere near the 100 line. I diluted 2x with distilled water and ran the test again. ~60, giving me a final number of around 120. Now I know the CYA test can be subjective but this means I'm still off the charts.

How is this even possible? if I'm at 100+ now, that would have put me near 500 before I started all this, clearly leaving me in a place where my pool was completely unmaintainable. Granted, I'd been popping powdered shock and chlorine tabs like they were going out of style...

I guess my only choice here is to replace half the water again, and maybe even again? How subjective is the CYA test? Any tips on optimizing it?

Thanks!!!

 

[pabeader]

If you want to perfect your CYA reading, you could order the 50ppm standard sold at TFTESTKITS.NET
Then figure out what you need to do to get the test to read 50. It is somewhat different for different people. Once you figure out how to get the standard to read 50, do the same thing with your water. That way you know it's the best read it can be.

 

[Texas Splash]

Hello and welcome to TFP. Appreciate the kind words. Even though your CYA appears to be high (still), take relief in knowing that now YOU are in charge with that test kit. Can you imagine trying to continue without it? Talk about blind management. But that's what many people do, then they place their trust in someone at a pool store who simply doesn't have a vested interest like you. So if you have to drain again to get into the 50-70 range (at least), then press-on. After that, you can check, double-check, triple-check your CYA if you have to. Make sure you're following all the CYA test rules:
- Hold tube at waist level
- Test outside with sun at back
- After your first attempt, pour back to the mixing bottle (shake) and do it again, 3, 4, 6 times! Get a good feel for when that dot disappears.

Once you know you're CYA is firm at a certain number, then you know for sure what your FC should be for a SLAM or just regular days. You'll get it.

 

[cbredesen]

- After your first attempt, pour back to the mixing bottle (shake) and do it again, 3, 4, 6 times! Get a good feel for when that dot disappears.

Once you know you're CYA is firm at a certain number, then you know for sure what your FC should be for a SLAM or just regular days. You'll get it.

I didn't think of this! I'm going to do this today. If my wife and I get different readings, I'ma order the 50ppm reference solution.

Thanks TFP!!!

 

[lefty51]

I think the CYA test frustrates the heck out of us new folks. I did get the reference solution to try and find the ideal spot to test. It still took me awhile.

Like TS said, test it several times and average your results. One other way to double check what you think is right, someone pointed out, pour in solution to say 90, then look for the dot, then add to 80 mark and look, etc. ( don't stare too long, just a quick glance, kind of gives you a feel for what it looks like). Of course you need to get your CYA below the 100+ level to get an accurate reading.

After awhile you'll get a "feel" for it, and get a reading you're confident in. Good luck, oh and Welcome to TFP, glad to have you aboard

 

[cbredesen]

I did a few iterations and also had my wife give it a shot. We arrived at around 90-100 ultimately and so tomorrow I'll do another drain halfway. Even at where it is now, it's better looking than it's been in ages and there's almost no stinging in my eyes. Can't wait to have it fully sorted out!

 

[YippeeSkippy]

As to how the CYA got high again, how were you "shocking" the pool? Granules? More pucks? Bag'oShock from the pool store? If they aren't all adding CYA, they're adding calcium to your pool.

The only way to avoid it all is to use liquid chlorine exclusively to clear up a sick pool.

 

[lefty51]

As to how the CYA got high again, how were you "shocking" the pool? Granules? More pucks? Bag'oShock from the pool store? If they aren't all adding CYA, they're adding calcium to your pool.

The only way to avoid it all is to use liquid chlorine exclusively to clear up a sick pool.

+1

liquid chlorine or plain old 8.25% bleach is all you need to sanitize

 

[cbredesen]

As to how the CYA got high again, how were you "shocking" the pool? Granules? More pucks? Bag'oShock from the pool store? If they aren't all adding CYA, they're adding calcium to your pool.

The only way to avoid it all is to use liquid chlorine exclusively to clear up a sick pool.

Pucks and granules all the way. No liquid. I'm really in awe that across 3 local pool stores (2 of them chains), nobody thought to tell me not to do this. Just mind blowing.

But I have seen the light

 

[pabeader]

The pool $tore can't make money only selling you chlorine. They make their money selling folks magic potions.