My FIRST test results and understanding CYA...(first post)

[TF Tim]

Hey everyone. I have been lurking on the forums for a couple weeks now and reading, reading, reading, but feel ready for my first post. I received my TF-100 test kit yesterday and did my first real testing this morning!

I am new to a 30,000 gallon (18x40') in ground gunite pool (more specs in my sig). Here is what I have done so far with a couple questions at the bottom:

Day one:
Opened the pool with a help of a 'friend' in the industry. Everything turned on great (except the Heat Pump which is another story). The pool was green with algae and couldn't see 1' down. Added DE to the filter but then switched the multi-valve on recirculate and shocked the pool (with powder from Home depot...). Was told to let the shock kill the algae without letting it get into the filtration alive.

Day two:
Got up the next morning and the dark green was now white and cloudy - just what I was told to expect. Seems like a good start. Added DE to my filter and let it run. Brushed the edges and bottom and let it sit. spent hours reading this site, decided to disregard most other advice from my local pool guy friend, and ordered the TF-100 test kit (and the magnetic stirrer).

Day three:
Still a little cloudy, but looking much better. Pulled the filter. Washed it gently with a hose. Re-added DE and then brushed the entire pool again (kicking up much less cloudiness). Later in the day figured out the vacuum and vacuumed to filter. Then figured out the polaris and let that guy run around a bit too.

Day four:
Woke up to a pool that one might call clear. Definitely progress. Filter pressure has been starting at 20psi and running to 28-30 within several hours. Backwashed and re-added DE - pressure is still on high side.
Added some 3" tabs to an auto-feeder and set it low. Operating under the assumption that the less I introduce into the pool until i have real test numbers the better. Until this point have been testing with test strips.

Day five:
Woke up to a pool that is crystal clear to the bottom. Could tell heads or tails on a quarter at 10 feet deep. BUT the pool does seem to have a pale greenish hue viewed in the pool - in a glass its crystal clear. My bottom is a darker gunite and it may be that. More on that below.

Day six:
Ran my first real test:

-CL: 0.5 just a trace
-PH: 7.5
-CC: 0.5
-TA: 130
-CH: 350
-CYA: ?????????


MY QUESTIONS:

1. Am I on the right track? Have i messed anything up yet?

2. Is it possible that I have no CYA? I think i did the test right, but the black dot seemed to get a little larger in the bottom of the vial but it in no way went away?

3. Based on my test results above I *think* I have done a pretty good job getting this open "gently". What should I do next? Assuming use pool math to determine how much bleach to add and then tackle CYA? Hoping someone can chime in to give me some confidence in my next move.

4. Is it possible that my water is green when it is clear in a glass. The three pics below are within minutes of each other. in the first its looking down 10+ feet (ignore the leaves now skimmed out) - the second looks greener - the third is looking at a sample. Any thoughts on what's going on here?




So I recognize this is a long first post - but it seems like you guys all like the details
Thank you so much for any thoughts. I have been an active member of several other online communities over the years.
I have enjoyed the journey from neewbie to a veteran and have always appreciated the help along the way and the chance to give back when I get there.
Thanks!
Tim

 

[Silver_2000]

Yes if you have new water or have never put stabilizer in or have a leak you could have zero cya

I did

 

[pinguy]

Yes, no cloudiness in the CYA test means 0 CYA.

"Shocking" alone usually will not rid a pool of algae. You need to Shock and Maintain until you pass the overnight FC loss test, CC <.5, and the water is clear. We call it SLAMing
Pool School - SLAM - Shock Level And Maintain

Before you do that though, you should make sure your CYA did not convert to ammonia (assuming CYA was in this water last season). This is done by bringing you pool up to shock level (FC=10 for no CYA), and measuring how much FC loss occurs in a 10 minute time-frame. If you see a large loss over this short time, you need to add chlorine & repeat every 10 minutes until the FC stays stable in that short 10 minute window. Then you can add CYA and SLAM normally.

 

[JVTrain]

You're off to a good start with the TF-100 and you are familiar with your equipment.

1. We don't recommend powdered shocks for the SLAM process, which you have started in a somewhat blind manner but you've done well so far.

2. It is possible you have very little CYA. The test is really only valid for values at 30 ppm or above. So you might have 5, you might have 10, you might have close to 20 but so far you're <30 ppm for sure.

3. Next, I would get a bit more CYA dissolving in the pool. You can cautiously assume you're at 10-20 ppm and add 20 ppm of CYA. Use Pool Math to calculate how much you need to add. Best to undershoot on CYA as it's easy to add, hard to remove. Put your amount in a sock (or two) and start it dissolving in the pool. Best ways are to put the sock in the skimmer or hang the sock in front of a return with a weight. Run the pump 24/7 until it dissolves. Lots of squeezing the sock will help it dissolve.

Adjust your pH to 7.2 using muriatic acid. Pool Math is your friend for knowing how much. Be sure to input your TA value into Pool Math while doing this as pH changes are TA dependent.

Then get some more FC in your pool using bleach. Plain, unscented stuff. Again, use Pool Math to target 12 ppm and make the assumption that your CYA is at 30 ppm once you've put it in the sock to dissolve. Repeat as often as you can following the SLAM procedure in my signature.

4. To me... the second picture looks green because of the trees in the background reflecting! The first pic looks very normal and blue. Keep at the SLAM procedure and you'll be confident in your clarity and color in no time.

 

[TF Tim]

Thank you for these quick answers!!! Think it all makes sense. I know starting off with the powder and tabs was...pun intended taboo...but i am learning quickly.

First step is to make sure ammonia is not an issue.
Then get some CYA going.
and finally focus on PH and FC.

I am actually having fun with all this!

You're off to a good start with the TF-100 and you are familiar with your equipment.
4. To me... the second picture looks green because of the trees in the background reflecting! The first pic looks very normal and blue. Keep at the SLAM procedure and you'll be confident in your clarity and color in no time.

Ahhh...in other words I am way overthinking all of this and probably need to settle down.

 

[TF Tim]

So what do I do now??? 3 questions.

First I cannot thank this community enough.

My first few weeks of being a "pool guy" has actually been a lot of fun. What's so cool is that every time I do something, what is supposed to be happening seems to be happening!

I started out with an algae swamp which I shocked and filtered with some success before really getting involved here:
http://www.troublefreepool.com/thre...anding-CYA-(first-post)?p=1018147#post1018147

My water cleared but was eating CL and had a green tinge...started reading about Ammonia...and quickly came to the conclusion that I had it.

After 20+/- gal of bleach (3 gal at a time) over a few days I went through several cycles where FC would stay basically 0 and CC reading would be high after a few hours. Kept at it ostensibly eating away at the ammonia. So far so good.

Saturday FC levels would rise with addition of bleach, but after a few (very sunny) hours they would fall to almost 0 - but good news was that CC was staying at O to 0.5. Made sense i knew my CYA was basically 0. Added 3.5 lbs of Borax (slowly over several applications) and by Sunday morning had CYA holding at ~40. As an aside, during this period PH fell from 7.5+ to 6.8 and TA came down as well to around 70-80.

Sunday morning, with CYA at a good level, started to SLAM in earnest. Each 3 hour cycle CL would go down from 10+ more slowly and CC was staying at 0. At 4pm added 3 gal to get to 10ppm. by 5pm was at 8ppm and at 8:15 was still at 5 ppm. Brought it back up to 12 at 9:00pm and it held at 8 ppm at 7:30 am Monday morning. All other readings good (but PH low).

I had to travel Monday - Tuesday. I retested this morning (Wednesday) and saw the following:
FC 1.5
CC 0.0
CYA 40
CH 325
TA 70
PH 6.8


So, if you have actually made it through all of that here is my question:

1. Is dropping from 12 ppm to 8 ppm over 12 hours (with 0 CC) too much of a drop to consider my pool "slammed"? If not, am i otherwise doing all the right things?


2. If I am looking good, at 1.5 FC now three days later and everything else relatively in line, what do i do next?? Monitor and add a gallon of bleach here and there as needed until i start to get a swimming load or other indication that another SLAM is necessary?


3. An thoughts on my PH are appreciated. Planning to add Borax but Poolmath is telling me 17lbs to get from 6.8 to 7.5...plan is to chip away at that slowly.


Any and all thoughts, criticisms (constructive or otherwise) are appreciated. I have a thick skin and am ready to learn.

thanks so much!

Tim

 

[Texas Splash]

Re: So what do I do now??? 3 questions.

Hi Tim. To help with your questions specifically:
1 - A drop of 12 to 8 is not unheard of during a SLAM.
2 - I do believe you need to perform a SLAM because while you increased FC briefly, you didn't appear to pass any overnight (OCLT) test
3 - pH is way low. Please raise that immediately with soda ash or borax to 7.2 in preparation for a SLAM

Based on your CYA of 40, your SLAM FC level is 16. It is imperative you maintain that FC of 16 24/7 while tending to the other requirements on the SLAM page (link below). Once you do those things and pass the 3 SLAM criteria, you have successfully completed the SLAM. Hope that helps.

 

[YippeeSkippy]

Re: So what do I do now??? 3 questions.

Borax does not raise CYA.

CYA raises CYA. Have you put some in?

Ditto on the pH being too low. That needs to be addressed pronto.

 

[jblizzle]

I merged your 2 threads. Please keep related questions together so we see the whole story. Thanks.

 

[pinguy]

Re: So what do I do now??? 3 questions.

Borax does not raise CYA.

I'm thinking he meant CYA.

2. If I am looking good, at 1.5 FC now three days later and everything else relatively in line, what do i do next?? Monitor and add a gallon of bleach here and there as needed until i start to get a swimming load or other indication that another SLAM is necessary?

You should continue the SLAM if your FC fell by 4 over night.

Also 1.5 FC is below the minimum level for your CYA, see here:
Pool School - Chlorine / CYA Chart