Help! possible black algae

[sugargirlz44]

ok, so i've been working on ridding this pool of green algae for 2 weeks and now i have black algae spots at the bottom. it's a plaster 11,000 gal. pool with a cartridge filter. i've kept it at shock level for a few days now, i also had to add stabilizer and baking soda to raise the alkalinity. i took som pics...
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thanks for the help

[CarlD]

Have you been brushing your pool daily to knock the algae loose? It's part of the regimen of fighting algae--brushing every day.

[wen95070]

Every year I have an outbreak of black algae even with perfect water chemistry. I now rely on shocking (>6ppm Cl) and shrubbing daily (as CarlD recommends) for a week with a wire brush to knock the slimmy protective "head" that forms and reduces the effectiveness of the Cl and copper algaecide. If a brush does not work, I use a pumice stone.

Once in awhile, I will add black algaecide that contains a couple of additional chemicals accompanying the elemental copper. Unfortunately, my spa becomes a bubble bath for a couple of days after.

Even when the black algae is dead, my spots do not immediately disappear, albeit they turn grey. More than one Leslie's Pool advisor has suggested I can rub a Cl tablet into the affected areas. But, my spots are usually near the bottom of the pool, so access is limited and Cl pool tips are hard to come buy(sic).

After a couple of weeks without new algae spots, I clean out my DE filter and recharge it.

Hopefully this helps.

[CarlD]

You'll need to post your chem levels. Don't be offended, but lots of times people come here and say "my levels" are good and they are anything but good.

The only algaecide we recommend is polyquat 60% (that's a type, not a brand).

I suspect, from the tinge of your water, that you need to re-evaluate your chem levels and use Ben's method of clearing algae. It's simple, but not easy--and you'll use ALOT of chlorine.

(I love "Rub it with a chlorine tablet"--did they BOTHER to tell you to wear heavy rubber gloves when you do, or the wet tablet will burn your fingers!)

[CarlD]

Jackie:
Please feel free to follow WaterBear's advice. Evan and I don't always agree but he's pretty darn good at this stuff and you'll be OK following it.

Please ignore Ugaguard's advice. It is generally useless and may be harmful. I hate to have to say that, but there's no nice way around that.

Carl

[sugargirlz44]

Thanks every1 for the advice, i finally got it cleared with ur help and with the help of waterbear who works at my local ace store :-)

[waterbear]

Knew you could do it...You've learned a LOT about pool maintenance in the past few weeks! Good job!