- Jun 24, 2021
- 16,466
- Pool Size
- 29000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
Stubborn Algae
- Thread starter Raseanw
- Start date
Good deal. A couple comments/questions:
- The FC/CYA chart calls for a FC level of 35 ppm when slamming with CYA of 90. It will drop quickly on you as algae consumes chlorine, so it's normal to test and see that it's under, but when you add chlorine, you're shooting for 35.
- The FC/CYA chart also recommends dropping CYA by draining or exchanging some water when your CYA level is 90. But if you're OK maintaining 35, then you don't have to drain.
- Do you mean CC (combined chlorine) instead of TC (total chlorine) ? TC cannot be less than FC, by definition.
This explains why the algae is not gone. SLAM level of chlorine for a CYA of 90 is 35. It's tough to keep chlorine that high.
A water exchange will bring the CYA down.
It is gone. It started to clear Monday and fully clear yesterday morning
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To get to recommended CYA level 60. About what percentage do I need to drain the pool?
Great progress.
You have CYA of 90, and you're shooting for 60. So you need to remove 90-60 = 30 ppm of CYA. 30/90 = 1/3. So drain off one-third of your water then refill with tap water. For a 4 ft deep pool, you're draining off 1 ft 4 inches.
You may want to go ahead and shoot for 50 rather than 60 just to keep more in line with TFP recommended levels. But some people around here keep 60 due to high sun exposure. So it's up to you.
Chlorine levels up to SLAM level are considered safe. You can read about that here. General guidance around here is if you can see the bottom it's OK to swim, though cloudy pools have some risk too according this article.
You have CYA of 90, and you're shooting for 60. So you need to remove 90-60 = 30 ppm of CYA. 30/90 = 1/3. So drain off one-third of your water then refill with tap water. For a 4 ft deep pool, you're draining off 1 ft 4 inches.
You may want to go ahead and shoot for 50 rather than 60 just to keep more in line with TFP recommended levels. But some people around here keep 60 due to high sun exposure. So it's up to you.
Chlorine levels up to SLAM level are considered safe. You can read about that here. General guidance around here is if you can see the bottom it's OK to swim, though cloudy pools have some risk too according this article.
Great thanks. You all have provided the best information and assistance. I want to make sure this never happens again. I will work on getting the CYA to 50. Afterwards, I will have some maintenance questions. Maybe post a new thread.
Just remember, moving forward until the CYA comes down you need to keep that FC between 10-12.
I was in the exact same shoes as you just two months ago. This place got me through it and I'm glad you're on your way to your own Trouble Free Pool.
But...You're not done with the SLAM yet!! Your CC is well above 0.5 and you havent indicated whether you've passed an Overnight Chlorine Loss Test yet.
So don't let off the gas yet or your pool is likely to turn green again soon.
But...You're not done with the SLAM yet!! Your CC is well above 0.5 and you havent indicated whether you've passed an Overnight Chlorine Loss Test yet.
So don't let off the gas yet or your pool is likely to turn green again soon.
Ok I’ll test tonight and restart in the morning. I had already drained my pool about a foot and refilled. It’s been an expensive week.
You want to continue use of Liquid Chlorine (found in the pool section of Walmart, or at Home Depot/Lowes, or "liquid shock" from pool stores) or plain, unscented, non-thickened, non-Chlorox type bleach (which is getting harder to find as its all been doctored up.)
When done with the SLAM-
Simple daily FC/CC test will help you get in tune to your pool water. You'll learn how much it takes daily, with more needed if a lot of swimmers or kids who pee are in the pool, perhaps less on days that are cloudy with no swimmers.
Here is the guide chart to follow --> FC/CYA Levels Pick the first tab that says "Iiquid chlorine".
Time to read up on pool care? Start here --> Pool Care Basics
Enjoy your pool now
Maddie
When done with the SLAM-
Simple daily FC/CC test will help you get in tune to your pool water. You'll learn how much it takes daily, with more needed if a lot of swimmers or kids who pee are in the pool, perhaps less on days that are cloudy with no swimmers.
Here is the guide chart to follow --> FC/CYA Levels Pick the first tab that says "Iiquid chlorine".
Time to read up on pool care? Start here --> Pool Care Basics
Enjoy your pool now
Maddie