Sue's Pool - ? about mustard algae

[ivyleager]

FYI....

One dose of "shocking" does not a cure make. I would bet that you'll need to maintain chlorine @ shock level for a day or two to make sure the algae problem does not reappear. The WalMart test kit does not test for CC, just TC. If convenient, take water sample to pool store and have them test, but DO NOT let them talk you into buying anything. Post the numbers and we'll assist further.

Good luck, and wear goggles!

CaryB

[Watermom]

CYA is cyanuric acid which is also called stabilizer. It would probably be a good idea for you to post a complete set of current water testing results taken with a drops based kit. Cary is right - if you go to the pool store to have your water tested, don't let them talk you into buying a bunch of stuff. And she is also right that one dose of shocking won't cure it. Keep at it for another couple of days and run your pump 24/7 for now.

[JohnInSoCal]

I had mustard algae and had a heck of a time getting rid of it. It wasn't a bloom, but it would grown on walls, steps, etc. and be back the next day or two. What finally worked for me was to add 1 qt polyquat 60, then get chlorine up to 20-25 ppm and hold it there for 2 days, run filter 24/7 and brush a couple times a day. After holding chlorine very high for 2 days I then let the chlorine drop down to 4 ppm, put in another quart of polyquat 60 and it's been fine ever since.

I think the main thing that helped was getting the chlorine up to 20+ for 2 days. Before I would just shock it and let it come down and while it did seem to kill the algae temporarily it always returned later. I have a pebble finish which is worse than standard plaster because this stuff gets into all the tiny nooks and crannies.

good luck.

[Sue's_pool]

HI Everyone!

Thanks for the great replies. Today I added a total of 3 gallons of liquid chlorine shock and one calcium based powder shock. I also brushed 2 times. This seems to have the algae in check so far. I will definitely keep up the chlorine levels and will keep BRUSHING, BRUSHING AND BRUSHING!

I went to our local pool store and the drop test only read chlorine levels up to 5! I ended up getting an advanced type of strip test and here are my results...

Hardness-400
Free Chlorine-higher than 10 (very dark purple!)
pH-7.6
Alkalinity-180
cya-30-50 range

One question still...What is polyquat???

Thanks again everyone. Hope you are all enjoying clear, warm, algae free water in your pools...

Have a great night,

Sue