can't scrub algae off sides and bottom

[kenmanblue]

have a 35,000 gallon in ground pool, and have maintained it since the beginning about 15 years ago. I never have issues with the color of the water, and have only occasionally had minor aglae problems, which is easily brushed off.

But this year, (a hot one in Michgan), I've had algae sticking to the sides and botton in "streaks" that I cannot brush off, except with long hard scrubbing in the shallow areas. Deep areas I have to use the pole with brush at the end, and its not enough to remove it. I should mention that the pool has had less use this year, which might contribute to the problem.

I use bromine, not chlorine, although the measure is about the same.
Bromine - 3.0
PH 7.5
Tot alkalinity 100

I clean the pool manually, but mostly with an Aquabot.

Part of the system is a hot tub, which never gets algae...I suppose because the water movement is great. I run the filter about 10 hours per day.

Everything seems correct to me, and the water is sparking clear but this green algae (presuming that's what it is) cannot be brushed off. Algaecide seems to do no good.

Any suggestions? I'm thinking next season I'll get the bottom and sides treated with muriatic acid so I can start the season without the algae or stains.

[fatybabe]

Ken i presume what you are using is BCDMH as treatment, your check is fine however I would recommend you raise the Bromine level to around 4.5 - 5 ppm since i beleive your pool is outdoors and Bromine cannot be stabalized so during especially hot summers it is better to add in da additional as a buffer.

Most probably what has happened with your algae is that it has rooted itself into your tiles so the algae comes right back after you clean the area.

A quick fix is to use a metal brush scrap the surface and take a BCDMH tablet with a bit of good old rubbing that should do the job.

Another point i would like to bring your attention to is yr circulation, try adding in a few extra jets to the places where you expereiincing the most algea bloom that will fix it permanently.

Some come back and post yr msg if you still exp. problems.