Why does a swimming pool turn brownish green after a torrential rain storm? How do you fix it?

Question

Recently there was a large amount of rain with some hail. The backyard flooded as the pool overflowed. Dirt washed into the pool. However, after a week of vacuuming and running the filter, the water remains greenish brown. The chemical balance tests normal. Any thoughts?

Answer 1

Clean the filter, may need to do this more than one time.

Use a product called YELLOW OUT (not yellow treat),

used per label with calcium hypochorite (shock)

will solve problem.

Answer 2

use an algaecide from any pool supplier. most are cheap and will control brown, green, and mustard algae

Answer 3

Rain falling through air loves to combine with the atmosphere it passes through, which contains around 70% nitrogen...

Algae LOVE nitrogen.

The brown is from the dust and debris caused to enter the pool by wind/water picking it up.

Shock the pool with chlorine - run the pump and change filter.

Answer 4

it sounds like algae.  For some reason, every time it rains, I have to add extra chlorine.  You would think fresh rain water would be nice and clean, but it does mess up the pool.