Singkirkan materi organik dari permukaan kolam. Cuci kolam dengan asam. Cobalah metode kejutan enzim dan gosok kuat-kuat untuk menyingkirkan noda. Kejutkan kolam dengan klorin. Singkirkan noda yang sudah dilokalisir dengan asam muriatic dan sikat kuat-kuat. Lewatkan solusi bahan kimia keras dan gosokan kasar.

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
Typically, greenish-brown colored stains are related to something organic like algae or leaves that were left on the pool floor. These substances need to be removed as part of the treatment. Organic pool stains are not usually hard to remove but with time, your pool will start to have a dull, light-brown color that you won't be able to remove. The brown discoloration happens very slowly and can be hard to notice at first.  If you have trees that hang over your pool, watch for leaves, branches, o