Is it suitable to use only one Nature2 Stick for a swim spa? October 24, 2017 02:43 Follow Depending on your swim spa but recommendation is 1 x Nature2 Stick for up to 2000L spa volume. For more details on Nature2 Spa Stick, click here. Related articles Is it ok to have the Nature2 Stick laying horizontally? If I have UV and Ozone systems, do I still need to use the same amount of sanitiser? Comments 0 comments Article is closed for comments.