Blue Lagoon for the 2nd year in a row


Well-known member
May 5, 2014
Not sure what I'm missing in closing, but I opened today to another blue lagoon.
Here are my numbers
fc 0
cc 0
tc 0
CH 175
TA 70
Ph 7.8
CYA 30

I've vac'd 5 inches of water to waste and stopped. Still lots left in the deep end. Should I hit it with Bleach tonight or wait until I can get more of it out tomorrow?



TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
If that was covered, the sludge in the bottom is just algae, not compost. If so, I'd start with the bleach tonight. Dead algae is easier to vacuum up. You also won't have sunlight robbing the FC overnight. I'd set the filter on recirculate so it doesn't clog up while you sleep.