You mentioned you're concerned about bottle bombs due to the CO2 in suspension. That Co2 is normal and expected, but if you let me know what your volume is, what temp your cider is at, and how much sugar is in your can of Concentrate, I can plug those in to a priming calculator and see if we can get you some reassurance.
Yeah the carbonation is quite strong when pouring it into a glass. When i put it in the gravity jar it was half an inch thick and stayed that way for a well over a min or 2. The other cider I did had very little carbonation when i poured it in the jar.
Not sure what you mean by the volume of the cider.
Its temperature has been a steady 58-60 just about the entire fermentation.
The concentrate I have is 29g per serving so 29x6=174g of sugar