OK water clearer now..explain this

[waterbear]

What is your CYA level and what is your pH?

[Madty]

CYA level is 28 (it was at the end of my post-sorry) PH is 7.8- had to raise for the yellow treat.

[JohnInSoCal]

Are you sure you have a mustard algae problem ? My mustard algae would come back the next day or two but never a couple hours later, that sounds like perhaps you have DE or dead algae in the pool. My mustard algae returned on the sides of the pool in certain spots and on a grotto shelf. I finally got rid of it by getting FC up to 25 ppm and using polyquat 60.

What kind of filter do you have ?

[Madty]

Are you sure you have a mustard algae problem ? My mustard algae would come back the next day or two but never a couple hours later, that sounds like perhaps you have DE or dead algae in the pool. My mustard algae returned on the sides of the pool in certain spots and on a grotto shelf. I finally got rid of it by getting FC up to 25 ppm and using polyquat 60.

What kind of filter do you have ?

Based on what it looked like, it was mustard algae. I have a sand filter- less than 1 year old. It looked like tan colored dirt. It would just poof away when you moved your hand near it. When I looked at it close, it was sorta slimy looking. Anyway based on web searches, it met the mustard criteria. I may try poly 60 in a few days just to see what happened. It's not dead, I believe, because I vacummed to waste and the next morning, it looked the same in teh same places- along the creases in the liner. My water has never gotten green either????

[JohnInSoCal]

ok that sounds exactly like what I had and it sounds like mustard algae, just seems strange the stuff would return after only a few hours. My water was never green either but I never had a cloudy issue either, not sure what your issue is there.

I just run the filter 24/7 for about 3-4 days, kept the chlorine at 25 ppm for 2 days, brushed every day, dumped in a bottle of poly 60% to start and then after a few days when the chlorine came back down I put in another quart of poly 60%. My pool is about 20K gallons. I also cleaned the filter (cartridge at the time). You may want to clean out your sand filter and replace the sand as part of this process. I don't have a liner so I don't know what level of FC is safe to prevent bleaching your liner, others will know that here.

good luck