Mustard Algae is causing a nightmare!

[gigaoranges]

Okay I'm having a SUPER TOUGH time dealing with this yellow algae growth. Here are my numbers with the taylor kit:

FC=12.
CYA=way above 100 even after diluting so I have no idea what it really is, but previous owner and my old pool guy just used the pucks. I have stopped and did a small 1/8(?) drain of the pool which removed 6-8 inches of water from a 25000 gallon pool.
pH=7.6-7.8
CH=havent tested this in a while.
CC=0
Haven't tested this one in a while but per leslie pool people phosphate was 300-400 ppm.

I have scrubbed my walls everyday, this yellow mustard algae is persistent and wont go away. I've currently put a pool tarp over my entire pool, added a ton of liquid chlorine to bring it to 12ppm. I just used a phosphate remover to starve the algae. Im tempted to buy algatec (not leaning towards this because it has CYA) or using this copper algacide (https://www.amazon.com/Rx-Clear-Swi...ywords=copper+algaecide&qid=1661746429&sr=8-3). Please help!!

 

[Deb04]

The chlorine isn’t touching the algae bc your CYA is so high. If your CYA was 200, you’d need to get your FC up to 79 to SLAM the pool and keep it there, which is next to impossible, and we know your CYA is above 200. The MINIMUM FC for a pool with 200 CYA is 15.

You know not to add anything with CYA, and adding anything with copper will stain things green, including blond hair. It also will give the illusion that your algae free pool is clean, but there won’t be enough FC to sanitize the water.

The only reasonable solution is to drain water and refill. we don’t know what type of pool you have and we can’t really offer advice on how to drain without that. Pls fill out your signature giving the type of info that’s in mine.

 

[wireform]

For starters draining 6-8" of a 25k pool with a way above 100 CYA is simply not going to make a dent in your problem. A FC of 12 for your CYA is a far cry from it doing anything and covering the pool with a tarp has nothing to do with attacking the algae. Firstly do the complete test lineup and post them here. The reason for the diluted CYA test so you should come out with a solid number of what it is and not guess it so we can guide you towards your next step. Trying to slam with that high of CYA will make the chlorine ineffective for a slam and you'll need an eighteen wheeler full of chlorine at best.

 

[duraleigh]

You must get CYA manageable.......less than 80 ppm.

All else is spinning your wheels. Please read "Pool Care Basics" up in Pool School

 

[proavia]

How are you testing your pool water?
What test kit are you using?

Pool Care Basics

With CYA >90, a CYA dilution test is suggested.

Water Testing Instructions - Further Reading

www.troublefreepool.com

Post a full set of current test results from one of the recommemded test kits.
Test Kits Compared

FC
CC
pH - FC needs to be less than 10 for accurate pH test
TA
CH
CYA
Water temp
Salt - if you have a SWG

 

[gigaoranges]

How are you testing your pool water?
What test kit are you using?

Pool Care Basics

With CYA >90, a CYA dilution test is suggested.

Water Testing Instructions - Further Reading

www.troublefreepool.com

Post a full set of current test results from one of the recommemded test kits.
Test Kits Compared

FC
CC
pH - FC needs to be less than 10 for accurate pH test
TA
CH
CYA
Water temp
Salt - if you have a SWG

using taylor 2006c. diluting the cya solution still makes it over 100. just to be clear, im shaking the small vial vigoriously for 30 seconds and then filling up the small column chamber immediately until I can no longer see the black dot, which is always over 100. If I let the solution settle a bit, then I can continue to fill it and have the black dot still visible within 100 CYA.

 

[gigaoranges]

does anybody have reasons against using copper algacides? I have a metal sequestering bag to counter the previous pool man's use of copper algacide, copper currently at 0ppm.

 

[proavia]

using taylor 2006c. diluting the cya solution still makes it over 100. just to be clear, im shaking the small vial vigoriously for 30 seconds and then filling up the small column chamber immediately until I can no longer see the black dot, which is always over 100. If I let the solution settle a bit, then I can continue to fill it and have the black dot still visible within 100 CYA.

Try a 2:1 dilution
2 parts tap water, 1 part pool water - multiply the results by 3.
If a 2:1 dulution results in a reading of 50, actual CYA is 150.

 

[gigaoranges]

Try a 2:1 dilution
2 parts tap water, 1 part pool water - multiply the results by 3.
If a 2:1 dulution results in a reading of 50, actual CYA is 150.

tried that, its still over 100. the last time i tested (before the recent pool drain), leslie said it was 90 CYA.

 

[PieterS]

Can you step us through step by step how you are doing the CYA test?

 

[JamesW]

tried that, its still over 100.

Mix a sample of 1 part pool water to 4 parts tap water, mix well and then test for CYA.

Multiply the result by 5.

 

[gigaoranges]

Can you step us through step by step how you are doing the CYA test?

Yes! I grab a sample of pool water 12 inches below the surface. I pour 1 part pool water into an empty container then pour 2 part tap water into the same empty container. Shake the container with both solutions and pour it to the 7 mark on the tiny bottle. I then take the CYA solution in the taylor kit and squirt it inside the tiny bottle to the 14 mark. I shake moderately for 30 seconds. I go outside with my back to the sun, the small chamber side at my hip and squirt the small bottle into the small chamber. I look to see when I no longer see the dot. The dot is long gone before it even hits the 100 CYA marker. The dot disappears halfway between the bottom and the 100 marker.

edit: i took my pool water to get tested by leslie an hour ago here are the results vs my previous water test and vs my taylor test.

FC: 8.59, vs taylor 8.
phosphate 568 (this somehow GAINED from 384 after i used phosphate remover)
TDS 600 (lowered from 3000)
copper 0.2 (somehow gained from 0.0)
Iron 0
CYA 110 (gained from 95, which makes no sense since I dont use pucks anymore, strict liquid chlorine only, and no other products that contain CYA) vs taylor >100 or 200.
CH 683 (stayed similar from 633)
TA 207 (similar from 201) vs taylor 210
pH 7.9 (7.8) vs 7.8.