I thought at first it was from the dirty pail and washed it both inside and out and then after several rinses, I realized that it was the water itself. It's still that way this morning but not as brown.
Al comienzo pensé que era de la cubeta sucia, la limpié por dentro y fuera, luego de enjuagarla varias veces me di cuenta que era el agua; sigue igual esta mañana pero no tan oscura.