New to TFP- am I on the right track?

[Sereguial]

Had the pool for 2 summers now. Last fall I saw problem after problem with my pool, figured I wasn’t filtering enough, or keeping up on chemicals. Well I winterized and then put her to bed because it was just getting too cold (clear, mostly). Well I opened her up recently (been a busy spring and hard plumbed the filter this year) and water was greener than previous spring. I added liquid chlorine and what used to be able to clear it up in a night only turned it a teal green now.
Well I got on the internet and found this website, started reading- holy molly did I not know what I was doing before! Well I ordered a test kit that I got Friday.

Here is my situation:
CYN - >100 ppm, I think. I’m having trouble figuring out when the black dot just disappears, if I backlight it (did the test at dusk one time) I got 80 ppm. Either way, it’s high. I’m wasting to just drawing air into skimmer and refilling to top of skimmer (done once refilling for the second time).
Running filter 24/7 at the moment, with auto vac running around (let’s me bring water down further at the skimmer).
Plan to SLAM following that.

Questions:
-Haven’t added any other chemicals (since I’m just going to waste them) should I be trying to regulate?
-Am I missing anything with measuring CYA?
-Is my plan sounding right?

 

[zea3]

Hi, welcome to TFP! the most important thing about the CYA test is consistency. You want to try to read the test around the same time of day in strong natural light with your back to the sun. It actually helps to not stare at the dot in the tube while running the test. Squirt enough to hit 100ppm, then look down in the tube. If you see the dot, look away and add more. If you don't see the dot, pour the solution back into the bottle and put in less. If you still don't see the dot you are over 100ppm and may want to run the test again using a 50/50 mixture of tap water and pool water for the sample.

You may find it is more efficient to drain water with a submersible pump, or get your vacuum hose and use the siphon method to drain water. (submerge the vacuum hose til it fills with water then quickly drop one end over the side of the pool) How high the CYA is will determine how much you need to drain.

 

[Sereguial]

Hi, welcome to TFP! the most important thing about the CYA test is consistency. You want to try to read the test around the same time of day in strong natural light with your back to the sun. It actually helps to not stare at the dot in the tube while running the test. Squirt enough to hit 100ppm, then look down in the tube. If you see the dot, look away and add more. If you don't see the dot, pour the solution back into the bottle and put in less. If you still don't see the dot you are over 100ppm and may want to run the test again using a 50/50 mixture of tap water and pool water for the sample.

You may find it is more efficient to drain water with a submersible pump, or get your vacuum hose and use the siphon method to drain water. (submerge the vacuum hose til it fills with water then quickly drop one end over the side of the pool) How high the CYA is will determine how much you need to drain.

Thank you on the feedback for the CYA test! I will redo it today with nice sun (nature willing) and do 50/50 mix if needed. In reading 50/50 mix method I should double the reading, right (80ppm line would mean 160ppm actual concentration)?
Once I get it figured out I will then figure out how much I need to drain. I would assume any standard dilution calculation would work? Based on my Navy experience we used CoVo+CaVa=CfVf equation. Co being initial CYA concentration, Vo being pool volume post drain (Vo=Vf-Va), Ca being amount in makeup water (should be 0ppm CYA right?), Va is amount of water drained and refilled, Cf is desired final concentration and Vf is total pool volume. Unknown here is Va or amount to drain. I will figure out height of water to drain to and then use the siphon method as discussed just leaving hose at the height to drain down to.
Would be best to "fail" low on CYA since I can always add, but taking away is a pain or should I be ok with a little high since I will be doing backflush throughout the summer and not using anything that will add CYA (at least not accidentally)?

 

[Rancho Cost-a-Lotta]

In reading 50/50 mix method I should double the reading, right

Correct

Once I get it figured out I will then figure out how much I need to drain. I would assume any standard dilution calculation would work?

No CYA in fill water, so a 50% reduction in volume equals a 50% CYA reduction

Would be best to "fail" low on CYA since I can always add, but taking away is a pain

I would aim low for the reason you cited. You can always add more if needed.

I've been using the CYA test for over three years now and I'm still not completely confident on my reading. As mentioned above, just be consistent. This may help:



Best of luck!

 

[Sereguial]

Correct

No CYA in fill water, so a 50% reduction in volume equals a 50% CYA reduction

I would aim low for the reason you cited. You can always add more if needed.

I've been using the CYA test for over three years now and I'm still not completely confident on my reading. As mentioned above, just be consistent. This may help:

View attachment 331761

Best of luck!

Well, got 80-90ppm (did it a couple times to be sure) when I started at >100ppm (dot went away well before I reach 100, but I was staring at it). That’s after two draw downs as described before. So I dropped it down to just under winterization level and I’ll see where that gets me with CYA tomorrow and then maybe I can start to clean it all up and get to enjoying the pool!

Thank you for all the help!

 

[DeanP66]

If you can get the CYA down to 50, you can stop right there and SLAM away with your FC at 20ppm. That's very doable. Most people in the hotter regions or with pools that get a lot of sun will run their CYA at 50 because it will keep the FC in the water longer than with a CYA down at 30.

One other reason you may continue to drain more is if you have a very high CH reading. I didn't see you post that number, but you definitely don't want it above 450 with a vinyl pool cause it could lead to scaling.