Black Algae Help..

Apr 15, 2018
Daphne Alabama
Good Evening,

Had a recent bloom of Algae just before the holiday weekend, its my fault for not keeping a close eye on it.... so proceeded to SLAM and clean the green algae. I noticed some black dots a few weeks ago didn't really register what it was. At that time I scrubbed with my nylon brush, however yesterday I noticed more black dots... I immediately jumped into 'pool school' to understand what to do next I did the white paper test which confirmed my suspicion.... raised my FC towards SLAM level ran down to the store picked up a stainless steel brush jumped in the pool with snorkel and mask scrubbed away every black dot went over the pool several times to make sure I had not missed any potential black dots.

This evening I did the same jumped in the pool rubbed areas black algae was present with stainless steel brush and went around several times inspecting for black dots to ensure I got everything... I don't think I seen a single black dot tested FC @ 11 then threw another gallon of chlorine in the pool. I have increased my pump run time on high to ensure we have good flow in the pool and I added some 'trichlor pucks' to keep chlorine higher whilst I'm working all day. I often use pucks in the high summer months just to keep on top of chlorine as with the amount of rainfall we have in Alabama it tends to level out over the year.

My main question is... I have cartridge filters which I cleaned not so long ago do I need to sanitize these somehow?

Ill continue to scrub and hold at SLAM levels for the next week....but I am confident I caught it early. I also know exactly how it got in there... living on the gulf coast about 50 minutes from Pensacola Beach its not uncommon for me to spend an entire day at the beach.... the perfect way to cool off my sun kissed salty skin is to jump into the pool when I get home.... I had no idea this is the most common way for Black algae to get in your pool.... in the future I think I am going to skinny dip instead.

FC 18
CC 0
PH 7.5
TA 90
CH 250
CYA 50

Open to suggestions...




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Oct 25, 2015
Palm City/FL
Pool Size
Salt Water Generator
SWG Type
CircuPool RJ-30 Plus

Looks like you're doing all that's needed. I had a small amount of black algae every now and then like you are experiencing. It only happened a couple times in areas that I know had low circulation and the FC got close to minimum. Did exactly what you are doing and a very short SLAM. Once I passed all 3 criteria dropped down to normal target and tried to never get below target. So long as I did this it never came back. Filter maintenance is totally unrelated. I'd clean it once or twice per year.

Looks like you've got this!

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