Persistent mustard algae patches

[MiaHudy]

Hi All, and thanks for reading,

13,000 gallon gunite kidney shaped pool. Stonescapes mini pebble redone in 2017.

I believe my CYA levels are too high but before draining out some water, wanted to check here first.

Using TFP test kit and included Taylor kit for chlorine and PH

Water Temp = 60-62
Just cleaned pool filter cartridges
Cl level is just above Taylor's top marker of 5.
Ph level is 7.4
CYA is somewhere between 70-80 depending on who is looking down the tube.
FC=3.5
CC=1

I have some patches of mustard algae cropping up on the face of steps in the shallows. I check chemicals every other day, and normally brush 1 - 2 times weekly, and this is usually enough. Now however the mustard algae, is coming back every couple days.

My plan is to drain about 50% of the water and re-balance the chemicals, keeping the CYA on the lower side. Before I go through the draining and refilling process, I wanted to check in here, to see if I'm on the right track.

 

[ajw22]

What test kit do you have? I suspect you do not have a TF-100 Test Kits or Taylor K-2006C. You need higher FC levels to deal with algae then what your kit can test. See Test Kits Compared

Also order the XL Option becuase with the algae problem you will use alot of reagent and the Speedstir Magnetic Stirrer to make testing easier and more accurate.

Your FC of 3.5 is way low for CYA 80. Your FC needs to be 9-11 normally and 31 to clear algae problems. See FC/CYA Levels

How do you chlorinate your pool?

After you drain your water and lower your CYA to 30 - 50 range you need to follow the SLAM Process to clear the algae.

I suggest you read ABCs of Pool Water Chemistry

Swimming Pool Algae: Basics and Prevention

The best offense is a good defense: prevent algae in your pool with chlorine, and avoid expensive algaecides and shock! No more green pools!

www.troublefreepool.com

Mustard Algae - Trouble Free Pool

Today We are going to show you how you can get rid of mustard algae in your pool. By following the steps in this guide and with no expensive chemicals.

www.troublefreepool.com

 

[MiaHudy]

My post stated I am using the TFP test kit and the included Taylor CL and PH kit.

Yes I have a chlorinated pool. Last summer I had used a few maybe 3 tri-chlor tabs in a floater for the stabalizer, but other wise I only use liquid Chlorine and liquid Muriatic Acid

 

[ajw22]

My post stated I am using the TFP test kit and the included Taylor CL and PH kit.

Why are you not doing the FAS/DPD chlorine test in the TF100?

 

[MiaHudy]

I did, as I stated in my original post with the results. I guess I did not make my self clear, but thanks for your help anyways.

 

[ajw22]

Ok, so drain the pool to lower the CYA and then follow the SLAM Process

 

[duraleigh]

Your test results make sense to me.

Assuming you do not have an SWG, then your CYA is too high and your thoughts on draining make sense.

You must address the algae more aggressively. Draining 50% of the pool should get your CYA down to around 30-40 which is perfect to begin the SLAM.

You can begin the SLAM as soon as your pool refills enough for you to get complete circulation.

So, drain the pool to get CYA to around 30-40 and then SLAM. Post back if the SLAM doesn't make sense or you need more assistance.

 

[MiaHudy]

Thank you for the feedback, I will be begin the drain today and go from there.