How many Nature2 Spa Sticks should I use in my swim spa? Sherralyn June 15, 2018 01:46 Updated Follow 1 x Spa Stick for up to 2000L of water, depending on your swim spa water volume, you may require more than one. For more details on Nature2 Spa Stick, click here. Related articles How do I mix spa chemicals? Comments 0 comments Article is closed for comments.