How much water should I put in the self-watering system? Clairy Support May 10, 2018 15:17 Follow You can fill the self-watering system until you see the white part of the float. Related articles How do I know when it's time to water the plant? How can I know that I entered the float correctly? What is the function of the strings? Should I use just one or both? Comments 0 comments Article is closed for comments.