New guy seeks CYA info

[Maydog]

I've been reading and learning here on TFP for a couple of months. I bought a house with a pool (see specs in signature) in early May and I am determined to at least keep up with the water chemistry and cleaning myself. My wife helps out by skimming out the big chunks most days.

Five days ago, I noticed that my water was getting a bit green. (I had gotten lazy about testing). So I tested (Taylor K2006 test kit) and my FC was at 1.0. CYA was 30 (or less) and pH was 8.0. I added muriatic acid and chlorine (10% benzalkonium chloride). I re-checked the next morning; pH was 7.5, FC was 2.5 (<0.5 CC). I added a bit more chlorine and 42 oz. (volume) of CYA stabilizer.

I checked this morning, and here are all my readings: FC 4.5, <0.5 CC, pH 7.5, TA 90, CH 160, CYA 30. Salt level has been in the 2900 range.

I guess my concern is that the CYA didn't seem to come up after adding stabilizer. I'm a bit scared of adding too much. My CYA may even be less than 30. When the tube is full, I can still barely make out the black dot. I thought I was testing wrong, but I read and re-read the directions...they aren't that complicated. 7ml test water + 7ml of the drops, mix for 30 seconds then add to the test tube. Not sure how that could go wrong.

Even with the low CYA, my FC is holding pretty steady and the water clarity is good again. If my FC is holding and everything else stays in a normal range, should I be worrying about a low CYA reading? Or should I keep adding it? FYI, I added the granular CYA to my skimmers.

Thanks, guys. I'm grateful to be able to learn from others with more knowledge and experience.

 

[woodyp]

ASSUME what you've added for CYA is in there. You just want enough that with your particular pool that you don't lose enough FC daily to fall below your minimum. [FC/CYA][/FC/CYA]
Welcome.

 

[Maydog]

Thanks for the input. I did read somewhere that it can take a week for the CYA levels to adjust for a test. I'll be patient.

 

[pookiesunshine]

... I added ... chlorine (10% benzalkonium chloride).....
I added the granular CYA to my skimmers.....

is the benz.. an algaecide? not a source of free chlorine.

if you added the cya in a sock it should all be in there. if you dumped the cya in the skimmer, it may not be all dissolved yet, depending on how long it has been. may be caught in the filter. if you backwashed soon after adding it that way, some of it is likely lost.

 

[harleysilo]

Have you backwashed since adding CYA?

 

[mknauss]

is the benz.. an algaecide?

Yes it is -- does nothing for a green pool, or any pool, for that matter.

 

[domct203]

Yes it is -- does nothing for a green pool, or any pool, for that matter.

And should never be confused as a sanitizer.

 

[Maydog]

Thanks for the responses. I've still never seen the black dot disappear when checking CYA. All I can tell is that it is less than 30. I assume the reagent is OK. I just bought the test kit (K2006) a few months ago, and I keep it inside my house. I just added another 3 lbs of CYA. I'll check it again in a few days.

 

[PhantomF]

Before adding all that CYA I would've made sure I could pass the Overnight FC Loss Test. If you need to do a SLAM it will be much easier with low CYA levels. It's hard to judge how much CL you were losing because you didn't specify how much liquid CL you added. Plus I assume the SWG is running and adding CL on top of that.

 

[Maydog]

According to Pool Math, the 3 lbs of CYA I added should raise the level by 18. Since I started below 30, I'll still be below 48. I do have some green algae. FC dropped from 5.0 to 3.5 in 24 hrs. I added the CYA and some more bleach (to get it back to 5.0) this morning. I'll re-test in the morning to see where I am.