your self-brough container has weight

Are my sentences grammatical?

-In this restaurant, there is a salad bar. Usually before 11:00, the staff will have placed the food in those containers below the lights. Right on the roof above the food, you will find a pair of scales. The staff will set the scales by using an empty dish, and after putting the food on the dish, you will see the price shown on the scales ($9/100 gram). If you want takeaway, you have to pay $2 extra for the plastic container they provide to you. You could bring your own container, but you have to be careful: your own container has weight, so before putting your own container with food inside it on the scales, you must tell the staff to offset the weight of your container on the scales, otherwise you would have to pay for your own container, because how much you have to pay depends on the weight of the food that you want to buy.