"The water is hard water so you need to put baking soda in the washing machine when you use it."
- "The water is hard water so you need to put baking soda in the washing machine when you use it."
"The water is hard water so ~" 「その水は硬水なので〜」
"you need to put 〇〇 in ~" 「〜に〇〇を入れないといけない」
"baking soda" 「炭酸ソーダ」
"the washing machine" 「洗濯機」
"when you use it" 「使うときに」