New guy here, need help with mustard algae...

[jason_b362]

So i have been having trouble with mustard algae for a while now, just cant seem to get it under control(new to owning a pool so not sure what to do exactly). 20,000 gallon pool, CYA around 80, FC a little above 10ppm. I tried bringing FC up (it was around 4ppm) but that doesnt seem to help. Should i be running the pool pump 24 hrs a day? or does that not really matter too much. Any help greatly appreciated.

Thanks

[aylad]

Hi, and welcome!!

Wth a CYA of 80, your normal chlorine range is 5-10 ppm, with a shock level of 20 ppm. Since mustard algae tends to be very resistant, some folks find that you have to take the chlorine up higher than that. So.. First step is to take your chlorine up to 20+ ppm, brushing the pool daily, and keeping it there until the algae clears and you're not losing any chlorine overnight. At that point you can let it drift back down to no lower than 5 ppm, but if the algae reappears you'll need to take the chlorine much higher.

[PoolDoc]

membership updated; thread moved to algae section. -ben
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Aylad pretty much answered your questioned, but you haven't posted back, so I-m not sure if you were put off by the answer, or didn't understand how to follow through. On the chance that you didn't know how to follow through (rather than simply rejecting the answer), I'll post two links that explain WHY you need to do what she said, and HOW -- testing-wise -- you can do so:
http://poolsolutions.com/gd/best-guess-swimming-pool-chlorine-chart.html explains the WHY;
http://www.poolforum.com/pf2/showthread.php?14994 explains what you need to test, or the HOW.