Chemicals advice- getting over a green pool

Jun 21, 2016
9
Sevierville/tn
I have a 25,000 gal saltwater pool that we are having issues with. It was chlorine when previous owners had it, but we had it converted to salt in April. The wrong size cell was installed for the hayward aquarite (the size for pools up to 15000 gal was installed). Our pool turned green and I had the water tested and someone come look at it, which is when we discovered the cell error. We will buy and have the right one installed, but even though the pool guy and I added a bunch of stuff to straighten out the pool, I'm not sure what else needs to be done. The water is looking better, but here are my stats (also my 1st time using the TF-100 test kit.

PH 8
CL 5 (I have a really hard time telling between the shades of yellow)

Free Chlorine 20 (even after 40 drops, still slightly pink tint)
combined Ch 7
Total 27

CH 350

Total Alkalinity 150

CYA test 40 ppm

Friday was when the pool guy, and I added a bunch of stuff to help balance it: 32 lbs sodium bicarbonate, 5 lb stabilizer (and a second 5lb bag added the next day), 1/2 bag of aqua salt, shock, 1.5 lbs soda ash. He also cranked up my chlorine on the Aquarite to 80% - we have issues since the cell size is wrong, but should I turn this back down now?

Any recommendations on further balancing out the pool would be wonderful!
 
Well, the first thing we need to do is get your pool algae-free that's for sure. And that will only happen with an accurate CYA and FC reading. Since those two are so critical, I'm going to just add a couple quotes for your to review and compare to how you did the tests yourself to see if they matched:
Proper lighting is important for the CYA test. You want to test for CYA outside on a sunny day, but keep the skinny view tube in the shade. Taylor recommends standing in the sun with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate the CYA reading.
For
FC, you use the 10ml sample with one heaping scoop of powder, then multiply drop count by 0.5 (or divide by 2) - Example: 20 drops from pink to clear = FC of 10.
As for the other products, please do not add anything else. Some of your levels are high enough already and don't need to be increased. We'll focus on the FC and CYA then come-back to other items later. :)
 
Well, the first thing we need to do is get your pool algae-free that's for sure. And that will only happen with an accurate CYA and FC reading. Since those two are so critical, I'm going to just add a couple quotes for your to review and compare to how you did the tests yourself to see if they matched:

ForAs for the other products, please do not add anything else. Some of your levels are high enough already and don't need to be increased. We'll focus on the FC and CYA then come-back to other items later. :)





Thanks! I'll rerun those 2 tests this morning. When doing the free chlorine test, I got it to clear but then looked back down and it was pinkish again so I tried to continues adding drops. At 40 drops it still had a slight pink tint. Any tips?
 
Once the FC test turns clear - record that number right away. Don't wait. If you let the solution sit, it will begin to revert back to pink on its own. So go with your first "clear" number. :)


Thank you. I use 26 drops so that would be 13 for the free chlorine. I used 4 drops for the combined chromides so that would be 2 for a total chlorine of 15 ppm I believe.

It's really cloudy out so I was going to wait on redoing the CYA test.

I should mention the green is gone from my pool, but it's still slightly cloudy.
 
Sounds like you're starting to impact the algae, but it's still there ..... lurking. The cloudiness and elevated CCs confirm that. Definitely maintain a SLAM FC level and follow all the advice on that SLAM page (link below). Once the sun decides to cooperate for you and you can verify the CYA under some good natural light, you can adjust the FC as required. Good luck!
 
We've done some new testing this season and determined that once the granules have fully dissolved from the sock, a majority of your CYA should show-up on the test within a day or two. If you want to be safe and wait a few more days to ensure you don't over-shoot your CYA that's fine as well. We are in the process of updating a few of our references to align with those recent test results.
 
I was reading in the pool school section and it said to wait a week to test CYA until a week after adding it. We added a 5lb bag Friday and another Sat so I guess I'll have to wait to test that one, right?

How did you "add" it? Was it in a sock by a return? Or did you dump it in a skimmer? Was it granulated CYA or liquid? (you said pounds, so I assume granulated but just wanted to be sure).
 

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Not only do you need to wait, but do not backwash your sand filter. If you backwash now any undissolved CYA in the filter will be lost.


I may have already messed it all up then. I brushed the pool and vacuumed it Sunday and had to backwash as part of that process. I thought I had ready that a pool that had turned green should be brushed and vacuumed daily until it was completely clear again.

- - - Updated - - -

I'll be honest, I'm pretty lost. I do appreciate all the help so far and any more suggestions
 
In that case let's go back to basics .... you showed a CYA of 40 yesterday evening, so let's use that for now. Make sure pH is adjusted to 7.2-7.4 then increase FC to "16" as a SLAM/shock level. You can always check the CYA in a few days to see if it increased, and if so, adjust FC at that time. But since you backwashed I'm guessing you lost most of what you intended to add - kind of a blessing in disguise now that you need to SLAM.

After the SLAM, remind us before you try to increase CYA as we'll instruct you other ways to add it. :)
 
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