CYA Testing Question

[pb4uswim]

I added stabilizer last night and tested this morning and it ‘appears’ that my level went down. The one thing I can think of is that it’s a cloudy day hear. So instead of having a bright sun at my back, it’s basically a gray day. Would that effect the ability to see the black dot? I sure seems like it. No sun here until tomorrow so just wondering if anyone else has experienced this. Otherwise, adding stabilizer decreased my CYA.

 

[BowserB]

Assuming you're sure you added cyanuric acid, then one of your test readings must be off, or as you surmise, the light made a difference. Frankly, I'm never absolutely certain I'm reading it right. However, like you I'm using a SWCG for chlorine, so if FC remains constant, I don't worry.

 

[mknauss]

It is best to wait 24 to 48 hours after the CYA stabilizer granules are fully dissolved to test for it. It takes time to disperse throughout the water column.

 

[Katygreys]

General consensus is to wait a couple days between CYA addition and measurement. Unless you have something consuming your CYA, it should go up after adding it.

Questions: What were your before and after readings? How much CYA did you add? Solid or liquid?

 

[pb4uswim]

General consensus is to wait a couple days between CYA addition and measurement. Unless you have something consuming your CYA, it should go up after adding it.

Questions: What were your before and after readings? How much CYA did you add? Solid or liquid?

I was at 50 and maybe 60 and I went down to 40. I was sooting for a solid 60 to 70. I added about a pound of solid. Sounds like it will be better to test tomorrow.

 

[mknauss]

A pound of dry CYA stabilizer will raise the CYA level in your pool by 8 ppm. The test, at its best, is +/- 10 ppm. So testing that change will be a challenge.

 

[pb4uswim]

A pound of dry CYA stabilizer will raise the CYA level in your pool by 8 ppm. The test, at its best, is +/- 10 ppm. So testing that change will be a challenge.

Agree, but I‘m getting close to 70 and I don’t want to over shoot. My last test, I was clearly at 50 but not quite at 60, so I thought I’d put in a little more in order to get a solid 60, which I’ve read here can basically be rounded up to 70 and stop there. Of course, the weird thing is that it went down (unlikely). I think it’s the light (lack of sun), but I did not know it takes a day or two before you should test, so I’m glad to have learned that.

 

[Katygreys]

Yea… this test is subjective enough as it is. Testing in consistent conditions can only help, and testing in inconsistent conditions can only compound the confusion