Am I OK?

[melted]

This is my first season with our new pool. Outside of my run in with the murky green monster back in March before we added any chemicals and before I knew anything about pool chemistry, all seems to be well. I would just like some verification that I'm running the levels properly because I read conflicting information. Plus I noticed this morning some scale formation on my zinc anode (is that normal???).

These are my test results from this morning and are indicative of what they have been for going on two months. The pool water has been crystal clear as well.

FCl - 1.50
tCl - 1.67
pH - 7.7
Alk - 96
CH - 179
Cya - 45

Pool temp is 83 degrees F and the salt level is 2900ppm.

I have the salt generator set at 50% and run the pump at night for about 10 hours. The pool gets direct sunlight from first light through 3 or 4 in the afternoon. We had a pretty good storm two nights ago. My main concern is the pH because in the literature from my test kit they call for 7.6 as the upper range. The pool calculator has the upper limit at 7.8! The scale on the zinc anode is what is bothering me, but the balance calculator puts me at -0.15 which I think is ok, right? I'm just looking for a sanity check. Should I lower the pH?

Thanks.

 

[woodyp]

You should boost your CYA to at least 60 and get the FC level to 3-4 range. Welcome!~

 

[duraleigh]

Welcome to the forum :lol: Ditto what woody said. Your FC should be your main concern, not pH.

You need a little more "cushion". About 3-4ppm and up you CYA to 60 and you can probably cut the SWG back to about 20-30% and save some cell life.

How are you testing? Obviously with something digital but is it your own or the pool store's?

You will probably need to lower pH pretty soon as it likely will rise but it's fine for now. When it goes above 7.8 or above, I would bring it back down to around 7.2 - 7.4 using muriatic acid.

The rest of your test results look good. Crystal clear water is VERY good, indeed! :lol:

 

[melted]

Thanks! I am testing with a digital kit (La Motte Color Q Pro 11), I ran concurrent tests on the same sample with my kit and the pool store's and mine was right on (maybe a little low on the Cl tests as compared to their results, but close).

Yep, I knew the CYA was getting a little close to the low end of the spectrum and I've been watching it drop slowly over the past two months. I have been running my chlorine levels around that 1.5-2.0 range because the folks at the pool store told me with an SWG and vinyl I could run with much lower chlorine than the normal 3-4ppm maintained in a tablet pool. So, y'all recommend that same 3-4 level even with my configuration?

If that is definitely the case then will the chlorine automatically come up once I get the CYA back up to the 60 range or do I need to go ahead and shock or super chlorinate it for a couple of hours?

Thanks again, I REALLY appreciate your help!

 

[melted]

Oh, and what do you think about the scale on the zinc anode? high pH or something else? should I be concerned? should I remove and clean it? if so, do you know how to clean it? I cannot find squat on the Internet about cleaning them.

Thanks.

 

[JasonLion]

You should either turn up the SWG percentage or supplement the chlorine produced by the SWG with additional chlorine added manually until the CYA level comes up. You need to maintain an appropriate FC level one way or another. There isn't any need to shock as long as the water continues to look good and FC hasn't fallen to zero. FC will come up on it's own as the CYA level increases, but unless you are raising CYA right away you shouldn't wait for that.

I have no idea why the anode would have scale on it. If it is calcium scale you can remove it with a dilute mixture of muriatic acid.

The appropriate FC level depends on the CYA level. With CYA around 45 you can indeed have FC around 2. But when the CYA level comes up you need a slightly higher FC level. Raising the CYA level will means the SWG doesn't need to run as much, so it will last noticeably longer.

 

[melted]

Ok, I finally got around to adding some stabilizer. (work travel - don't you hate it when work gets in the way of what you really want to do?)

I tested Friday night and the FC level was alarmingly low (0.3??) and the Cya at 43! I superchlorinated for 3h and bumped the cell to 60% to run for 10h over night on schedule. I tested again Saturday night and the FC had come up to 0.94 Cya still at 45. I added a gal of liquid stabilizer, set the cell to superchlorinate for 3h and went to bed. These are this morning's test results:

FC - 2.86
tCl - 3.02
pH - 7.7
Alk - 103
CH - 188
Cya - 56

The pool temp this morning was 86 deg and the salt at 3100ppm.

I will test again tonight to see how the FC holds after a day of sun, but I think I'm golden. Thanks for your help.

 

[duraleigh]

I would run FC in that pool no lower than 4ppm ever. Because you have let it get too low (probably more than once) you could have some invisible algae growth causing the swg to work overtime. Next time your FC dips too low. boost it back with Clorox, not the swg. The swg takes too long. The Clorox will do it in five minutes.

 

[Bama Rambler]

If you find that you're having to run the swcg higher than previously after you get the CYA up you should run the OCLT to make sure you don't have a bloom beginning.