Whilst following my first batch of home brew instructions, rather than using a Priming Calculator we added the amount recommended for bottling (1/2 teaspoon per pint). It's been in the pressure barrel around 4 weeks and is very low on CO2, poured a pint off which had some kick from the tap and then it glugged. The ale is also fairly cloudy.
I tried adding a CO2 bulb in the top, this resulted in a good 1/2 pint then back to the above.
Given the batch has been in the pressure barrel for 4 weeks and I know I added around 15 teaspoons to the brew - what is the best way to try recover this underprime. Should I try adding more CO2 bulbs, or is it worth adding more sugar and trying to restart the secondary fermentation? I should also point out the barrel is well sealed with vaseline on all the joints.