I know what I’m doing, but you are right to be concerned. It can be tricky to fill them not only because they need to be filled with liquid not gas but also because SodaStream has this weird type of proprietary “anti-fill” cap on them, and if CO2 flows into them too rapidly it locks out the bottle. So to do this effectively, you not only need the adapter but also a throttleable valve, more finely throttleable than the main tank valve.
I don’t have my numbers in front of me so I am making up these numbers, but essentially the process starts with a bottle’s overnight stay in the freezer. If you don’t chill them down ahead of time, you can’t fill them to full capacity. Then they go on the hanging scale with the adapter on, empty the weight is something like 1040g (which is the bottle + adapter). Then I fill them to 1440g (which is bottle plus adapter + 400g CO2). I always fill to 400g of CO2 instead of 410g to play it safe. So I leave off the last 10g. I’m not sure how I would trip it but I want to avoid possibly popping the bottle’s rupture disc, maybe if they’re left in the sun all day?
My tank does have that dip tube, it’s called a “siphon tube” and it ensures that I pull liquid from the large tank. I’ve been doing this for years - I can feel the weight and the change in CO2 filling flow by hand this point. My scale’s battery died at one point and so I was ballparking it. After later replacing the batteries, I weighed a few of my filled tanks and I was within 25-50g (and I intentionally slightly underfilled them to play it safe).
When I started this it took a couple minutes for each bottle but now I have it down to a science, how much I can throttle fill without tripping the anti-flow valve.
I know what I’m doing, but you are right to be concerned. It can be tricky to fill them not only because they need to be filled with liquid not gas but also because SodaStream has this weird type of proprietary “anti-fill” cap on them, and if CO2 flows into them too rapidly it locks out the bottle. So to do this effectively, you not only need the adapter but also a throttleable valve, more finely throttleable than the main tank valve.
I don’t have my numbers in front of me so I am making up these numbers, but essentially the process starts with a bottle’s overnight stay in the freezer. If you don’t chill them down ahead of time, you can’t fill them to full capacity. Then they go on the hanging scale with the adapter on, empty the weight is something like 1040g (which is the bottle + adapter). Then I fill them to 1440g (which is bottle plus adapter + 400g CO2). I always fill to 400g of CO2 instead of 410g to play it safe. So I leave off the last 10g. I’m not sure how I would trip it but I want to avoid possibly popping the bottle’s rupture disc, maybe if they’re left in the sun all day?
My tank does have that dip tube, it’s called a “siphon tube” and it ensures that I pull liquid from the large tank. I’ve been doing this for years - I can feel the weight and the change in CO2 filling flow by hand this point. My scale’s battery died at one point and so I was ballparking it. After later replacing the batteries, I weighed a few of my filled tanks and I was within 25-50g (and I intentionally slightly underfilled them to play it safe).
When I started this it took a couple minutes for each bottle but now I have it down to a science, how much I can throttle fill without tripping the anti-flow valve.