Greenish water - please help!

[joynun]

Hi! We had iron stains in our gunite pool a few weeks ago. Did AA treatment and it took about a week for water to get un-cloudy. Water tested great and was crystal clear for several days. Today we noticed a greenish tint to the water. Tested again, and again, numbers look good to me (results attached). Unsure what’s causing the greenish look and what to do?? Please help!

 

[Texas Splash]

Can you post a picture of the water?

 

[joynun]

 

[joynun]

Here’s a “normal” pic for reference:

 

[Texas Splash]

The pics help paint a better picture. That recent pic does confirm dull looking water with a slight green. Your CYA is certainly much too high and I would bet your FC level (or SWG) cannot stay balanced per the FC/CYA Levels - thus resulting in algae.

Do you know how the CYA got so high? You'll have to exchange some water first to lower the CYA before you begin a SLAM Process.

 

[joynun]

Thank you so much for your response. How would I know how much water to replace?

Also, I’m not sure how my CYA got so high. We added the suggested amount of stabilizer last week per Pool Math.

 

[Texas Splash]

How would I know how much water to replace?

The first thing I would recommend is confirming exactly how much over 100 your CYA is using the link/note below. As an example, if you get a diluted CYA of 70, you know your CYA is actually 140. If you exchange 50% of your water, the CYA should lower by about 50%. The PoolMath APP's "Effects of Adding" can help you as well. While you have a salt pool and a CYA of 70 is ideal, it does require a higher FC SLAM level. So it's up to you as to how much water you want to exchange to lower the CYA. Anything at 70 or below for the SLAM is acceptable.

CYA - Cyanuric Acid Test

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

www.troublefreepool.com

1. If your CYA level is 90 or higher, repeat the test adjusting the procedure as follows:
   1. Fill the mixing bottle to the lower mark with pool water.
   2. Continue filling the mixing bottle to the upper mark with tap water.
   3. Shake briefly to mix.
   4. Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark.
   5. Continue the test normally from step 2, but multiply the final result by two.

 

[joynun]

Thanks SO much!! We’ll get to work…