CYA Test Reading Question / New Pool Owner

[TurboBoost]

Hey everyone!

As the title suggests, I am a green pool owner (both the amount of time I've owned a pool, and the color of the water!). The pool itself is a 13.5K gallon above ground, with a sand filtration system and a Hayward Chlorine Feeder.

I have been regularly vacuuming the pool and decided to begin a SLAM. I thought I got the Chlorine level high enough, but I don't think I did because the pool is now green. So I'm starting over again.

My current PH and TA levels seem to be okay per both the test strips and the TF100 test kit that I bought.

My current FC level is 3.5 PPM, and where I'm very confused is with the CYA test.

If I hold the bottom of the tube against a background that is light (but not super bright), I'm not seeing the black dot somewhere around 90-100. However, if I hold the bottom of the tube against a brighter background (like the light from a lightbulb), I'm reading about 45. Which is the proper way to read this test? I'm about ready to head to the pool store to get my test results verified, but figured it would be worth a check here first.

If my CYA is the higher level, then I think it best to get that down before attempting another SLAM (per my reading on here). Really hoping to avoid that though, as I'm on a well system. I attached a couple pictures as well, just for reference. Thanks in advance for any advice!

 

[mknauss]

Which is the proper way to read this test?

CYA - Cyanuric Acid Test

Cyanuric Acid (CYA) is the chemical name for what is commonly referred to as Stabilizer … Read more…

www.troublefreepool.com

Once you have your solution ready, back to the sun, etc. Fill the vial to a line, say 80, lower the vial to your waist level and glance for the dot, you see it, add solution to the 70 line, glance, see it, repeat until you no longer see it with a glance. Then use the CYA value one step above the line you read. So if you stopped at 50, use 60 ppm CYA.

The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....

Do not use the test strips. They are not accurate.

Add 5ppm FC worth of liquid chlorine tonight. Do the CYA test as described above tomorrow.

 

[Btrimble]

CYA - Cyanuric Acid Test

Cyanuric Acid (CYA) is the chemical name for what is commonly referred to as Stabilizer … Read more…

www.troublefreepool.com

Once you have your solution ready, back to the sun, etc. Fill the vial to a line, say 80, lower the vial to your waist level and glance for the dot, you see it, add solution to the 70 line, glance, see it, repeat until you no longer see it with a glance. Then use the CYA value one step above the line you read. So if you stopped at 50, use 60 ppm CYA.

The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....

Do not use the test strips. They are not accurate.

Add 5ppm FC worth of liquid chlorine tonight. Do the CYA test as described above tomorrow.

THANK YOU, THANK YOU, THANK YOU. I was like do I use one eye or two? Is the dot supposed to be gone gone or just a lightly there. This totally helps. Back to the sun, vial at waist level, glance. I'm thinking my CYA isn't as bad as I thought it was. :0) I'm checking again tomorrow.

 

[TurboBoost]

I retested my CYA and it is at 80 using the method described above. I've drained some water and replaced it, but still a bit high. Unfortunately doing a partial drain and refill isn't an easy option at this time, so I decided to attempt a SLAM again.

After confirming the pH level is correct, I brushed the pool wall, vacuumed it, backflushed the sand filter and boosted the FC up to shock level (it's currently a bit above, at 35PPM).

Finally, I think the water might be starting to get less green. Hopefully this does it!

 

[mknauss]

Be sure you have lots of R0871 reagent on hand.

 

[TurboBoost]

Be sure you have lots of R0871 reagent on hand.

Yep, I got the high capacity test kit, so I'm good on R0871.

The pool seems to be a fair amount less green today. I brushed the walls and floor again and will vacuum later.

Does anyone have a good way of telling when filter sand needs to be replaced? I may just need to be more patient, but I'm concerned at how slowly this process seems to be progressing. It could also be the higher CYA level causing this (currently 70 per this mornings test)

 

[mknauss]

Filter sand should never need to be replaced. Only the addition of pool store potions (floc, clarifier, etc) will gum up the sand.

 

[TurboBoost]

Filter sand should never need to be replaced. Only the addition of pool store potions (floc, clarifier, etc) will gum up the sand.

That's what I figured. I did find some floc and clarifier in the closet from the previous owner though, so I wonder if the sand did get messed up before I owned the house.

 

[TurboBoost]

Update: The water is not very green any more, but still pretty cloudy beyond about half way beneath the water line. The floor is not visible, at this point.

My FC is still at SLAM level that corresponds with the current CYA, and I've been performing regular brushing, vacuuming, and backwashing.

The one thing that I did screw up is that I measured pH again after beginning the SLAM, and added a dose of MA. I understand where I went wrong there and won't mess with it again during SLAM.

My question is, if I messed up my pH level while a SLAM is underway, could that cause the cloudiness in the water? I'm wondering if I need to let the FC level drop so that I can rebalance the pH, or if I should just keep going with my routine.

 

[mknauss]

Test your TA.

 

[ajw22]

CYA Testing - Further Reading

www.troublefreepool.com

 

[TurboBoost]

Test your TA.

Is the TA test reliable during SLAM (unlike pH)? Is there a correction between an incorrect TA level and the water not completely clearing?

Thanks in advance!

 

[mknauss]

The TA is valid, you may have different color changes. See Total Alkalinity - Trouble Free Pool

I am asking because if the TA is above 50 ppm or so, the pH cannot be too low, at least for long.

The TA and pH will have nothing to do with your pool clearing up in your situation.

 

[TurboBoost]

The TA is valid, you may have different color changes. See Total Alkalinity - Trouble Free Pool

I am asking because if the TA is above 50 ppm or so, the pH cannot be too low, at least for long.

The TA and pH will have nothing to do with your pool clearing up in your situation.

Interesting!

I did the TA test this afternoon, and got puzzling results. The water started out blue and went clear, before turning yellow. That is expected per the test instructions, but according to the test, the TA level is currently at 370!

The water is looking less and less green, but definitely still cloudy. I know I need to keep up with the brushing and vacuuming, I'm just not sure if I should let the FC fall to rebalance the pH and TA at this point, or forge ahead.

Currently, FC is at 28 with CYA at 80. Started the day at 32.

 

[mknauss]

Do not worry about pH or TA. Deal with them after you pass the SLAM criteria.

 

[TurboBoost]

Do not worry about pH or TA. Deal with them after you pass the SLAM criteria.

Roger that... Back to vacuuming!