If you have RO or distilled water you have near ZERO PPM.
This means dissolving stuff into it is so much easier.
- Add all ingredients to the Zero PPM water
- Co2 charge a bit allowing time for the Co2 to bind with the solids
- Keep charging until the full charge is in for a 2L bottle
- Then refrigerate
I don't have a Soda Stream but that is what I would do.