1. Introduction

Everyone knows Sodastream, and if you don't here is the official webpage: https://sodastream.com/. When dealing with sparkling water you have two choices: to buy bottled water (typically in 6-pack) or to produce sparkles yourself by adding CO2 to the tap water. The question is whether Sodastream has more advantages over bottled water apart form the environmental benefits.

2. Purpose

The aim was to predict how much money can be saved by using Sodastream as compared to bottled sparkling water, and how fast can investment be returned. The simple prediction was done using Autoregressive integrated moving average.

3. Data Set Information

The prediction was calculated for the period of 20 years. The price for bottled water is constant so that the line is non-stationary. The Sodastream total price was calulated as a device price + CO2 container (changed after every 60 l of water) + (new device) for each 2 year period. You can easily change the values to recalculate the predictions.