Mustard Algae problem

nityntiy

Well-known member
May 17, 2016
115
Dallas, TX
Newbie Pool owner from Dallas, TX.

14400 gallon vinyl pool, PentAir Clean and Clear Cartridge filter, Polaris 280 pool cleaner.

I neglected my pool over the past several months during winter. Now I have severe Algae problem. I am currently using Walmart brand Great value bleach (concentrated 8.25%, 121 oz). I tested my FC this morning at 8 am after dumping 2 full bottles of bleach last night around 9pm. It reads 0.5 ppm. My CYA is zero I believe. On testing using Taylor Kit 2006, the black dot was still visible even after filling up the test kit container fully. So I added some conditioner this morning (2lbs) as per directions. Also dropped 3 trichlor tablets on the pool.

Now here are my questions:


  1. Do I need to wait for CYA to rise before adding more bleach? It’s been cloudy/raining here lately, so not much sunlight during day time. Also it rained last night after I added bleach.
  2. I read that Algaecide has side effects. So just stick with bleach to address this issue?
  3. Currently I plan on adding 2 more bottles of bleach tonight to raise the FC. Or should I get store brand shock?(calcium hypochlorite)
  4. My PH was above 8 last night. I ended up adding too much Muriatic acid. Now the PH reads 7 or below. Is that Ok? Or should I raise it before adding bleach?
  5. I have yellow/greenish sand like particle (mustard algae) all over pool floor. But I brushed off the ones from the walls/steps etc. Will the Polaris pool cleaner be used to vacuum the algae from the pool floor? I don’t have another means of vacuum as of now.
  6. I haven’t cleaned the filter yet since I bought the house 2 years ago. Newbie on owning and maintaining a pool. Should I hire a pro? I don’t want to open it and break something especially with this Algae situation. Can I wait until the problem is fixed to clean the filter?
  7. My readings:

FC : 0.5 ppm
PH : 7
TA: 75(tested last week)
CYA :0

  1. In what order should I balance the chemicals? CYA, FC, PH, TA?

Thanks in Advance for all the tips. Really appreciate it guys.
 
Hello and welcome to TFP! :wave: First I'll answer your specific questions:
1 - No. You adjust FC based on the target CYA you projected for
2 - Correct
3 - The Great Value bleach you are using is perfect
4 - A pH of 7 is okay. If it's below that you might want to aerate a bit or add a little borax/soda ash
5 - If that is indeed MA, we'll come back to that at the end of the SLAM.
6 - You should clean that DE filter, and you can do it on your own. We have threads here to illustrate
7 - First thing I want you to is the following:
1. Begin a SLAM and dose FC up to SLAM level. If your CYA test is showing as zero (perhaps already converted to ammonia), use a SLAM/Shock FC of 10. Do not add additional CYA at this point.
2. Retest FC at 10-minute intervals.
a. If FC loss is greater than 50%, add FC to bring back up to SLAM level and continue retesting FC @ 10-minute intervals.
b. IF FC loss is 50% or less, add FC to bring back up to SLAM level. Go to Step 3.
3. If CYA is below 30 ppm, add enough CYA to bring level up to 30 ppm.
4. Continue SLAM as directed in the SLAM article until the SLAM Criteria of Done are met. Test as directed in the SLAM article - no longer need to test FC at 10 minute increments at this point.
That will rule-out ammonia and allow your FC to hold better. You want a CYA of 30 and FC of 12 during your SLAM. We'll come back to the filter once you've had a change to digest all of this. :)
 
Hello and welcome to TFP! :wave: First I'll answer your specific questions:
1 - No. You adjust FC based on the target CYA you projected for
2 - Correct
3 - The Great Value bleach you are using is perfect
4 - A pH of 7 is okay. If it's below that you might want to aerate a bit or add a little borax/soda ash
5 - If that is indeed MA, we'll come back to that at the end of the SLAM.
6 - You should clean that DE filter, and you can do it on your own. We have threads here to illustrate
7 - First thing I want you to is the following:
1. Begin a SLAM and dose FC up to SLAM level. If your CYA test is showing as zero (perhaps already converted to ammonia), use a SLAM/Shock FC of 10. Do not add additional CYA at this point.
2. Retest FC at 10-minute intervals.
a. If FC loss is greater than 50%, add FC to bring back up to SLAM level and continue retesting FC @ 10-minute intervals.
b. IF FC loss is 50% or less, add FC to bring back up to SLAM level. Go to Step 3.
3. If CYA is below 30 ppm, add enough CYA to bring level up to 30 ppm.
4. Continue SLAM as directed in the SLAM article until the SLAM Criteria of Done are met. Test as directed in the SLAM article - no longer need to test FC at 10 minute increments at this point.
That will rule-out ammonia and allow your FC to hold better. You want a CYA of 30 and FC of 12 during your SLAM. We'll come back to the filter once you've had a change to digest all of this. :)

Thanks Texas Splash. Really appreciate the tips.:D

But since raising CYA takes time, can I still go ahead and add bleach to raise the FC or wait until CYA reaches 30 ppm? Currently it might be zero. I don't want to waste the bleach if CYA needs to be balanced first.
 
Once you perform the 10-min ammonia drill above, you are ready to SLAM like normal. You can add the stabilizer and go ahead an increase FC to that SLAM level right away as noted. You're not swimming so it's fine. We also found that stabilizer, once fully dissolved, shows-up on the CYA test much faster than previously believed - most of it between 24-48 hours or so.
 
Once you perform the 10-min ammonia drill above, you are ready to SLAM like normal. You can add the stabilizer and go ahead an increase FC to that SLAM level right away as noted. You're not swimming so it's fine. We also found that stabilizer, once fully dissolved, shows-up on the CYA test much faster than previously believed - most of it between 24-48 hours or so.

Thanks Texas Splash. I am currently at work. Will do that this evening.
 
Ok. So I added baking soda to raise TA from 50-60. PH was increased from 7.0 - 7.2

Then I added 1 bottle bleach (8.25%) and after 10 minutes the reading was
FC: 9 ppm
CC:0.5 ppm
TA:60
PH:7.2
Hardness: 200ppm

After 10 minutes, the FC dropped to 8ppm. Added another half bottle bleach again.

Next reading, FC went upto 14ppm.

Picked up another 10 bottles of bleach at Walmart.

30 minutes later reading is
FC: 12.5ppm
CC:0.5 ppm
TA:70ppm
Didn't measure ph.

So I assume I need to keep adding chlorine until FC stops dropping below 1 ppm for several hours? How often do I test now?

The green color is gone, but the water looks cloudy. I read it could be dead Algae. Is that so?

The forecast is rain tomorrow. Do I need to keep testing and add chlorine in that case? What level FC should I maintain moving forward?
 
Nope, you're good. No need to do the 10-min drill anymore. There is no ammonia. Now you're on to the normal SLAM. If you have no CYA or haven't added any stabilizer yet, make sure your CYA is targeted for 30 ppm right away, then just maintain an FC of 12. You don't have to test every 10 minutes any longer. Maybe every hour or two at first, but later it will back-off to more than that. You'll see a pattern of how fast FC drops during the day, then just bump it back to 12. Good job!

Oh, and rain or no rain ... the SLAM continues! Raaaaahhhhhh! :)
 
Nope, you're good. No need to do the 10-min drill anymore. There is no ammonia. Now you're on to the normal SLAM. If you have no CYA or haven't added any stabilizer yet, make sure your CYA is targeted for 30 ppm right away, then just maintain an FC of 12. You don't have to test every 10 minutes any longer. Maybe every hour or two at first, but later it will back-off to more than that. You'll see a pattern of how fast FC drops during the day, then just bump it back to 12. Good job!

Oh, and rain or no rain ... the SLAM continues! Raaaaahhhhhh! :)

Thanks Texas Splash.:)

After 2 hours, just did another test. FC dropped to 10.5 ppm from 12.5 ppm.

I did add CYA this morning directly to skimmer. It's still there undissolved. CYA is below 20ppm I guess.
I will do another test in an hour and will add chlorine again.
 

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Another hour later FC dropped to 10 ppm and CC 0.5 ppm.
Added some more bleach. Will test again tomorrow morning.

One thing I'm confused is FC keeps dropping but CC stays steady. Shouldn't CC be increasing to compensate the FC drop?
 
CC won't always react the same with FC. You would think so but it doesn't. CC will fluctuate during a SLAM, and the amount of sun received each day will influence that as well. You're doing well to watch and maintain that FC. That's the most important part. Have a good day.
 
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