I appreciate that the question is aimed at Gareth, but I thought I would answer because I've modified my own system as per the photograph...............
As a thought do you think it would be possible to connect a standard pub bottle up to the keg so that I can just use the mini cartridges for dispensing beer ?
The non-return valve on the Growler is defeated when it is connected to the CO2 bottle so when the CO2 is connected to the Sodastream CO2 bottle the "non-return" function is transferred to the Regulator as per this photograph.
To overcome this situation:
- I carbonate the Growlers with Pressure Relief Caps which means that I can leave them to condition for months, knowing that they are carbonated enough to prevent any spoilage.
- The low level of carbonation results in very little trub. It also removes the problem of foaming when it's time to de-pressurise, remove the PR cap and insert the dip-tube/tap. (When the Tap is installed, I then put the Growler under CO2 pressure.)
- The carbonation of 1g per litre results in very little trub at the bottom of the Growler. As shown in the photograph, the attachment on the end of the flexible dip-tube stops it sticking to the bottom of the Growler and the only time I get any trub into the glass is in the first 100ml.
All I can say is that the system I have cobbled together works for me and hand you over to Gareth for further advice.
I have one of the new "spring-loaded" taps and it works great using the same system.