How much pressure to keep carbonation?

[foxtrot]

I just completed a 5-tap keezer with faucets and 5' of 3/16" liquid line for each keg. I have a 5-port manifold feeding the kegs. My issue is foam and too quick a pour with the reg set at the typical 12 psi. I have to reduce the psi to about 3-5 in order to get a non-foamy, decent pour. My question is, at this low psi, will the carbonation eventually deminish over time? If so, is there a calculation to determine the required "head pressure" to keep a beer at a certain carb level?

 

[TelemarkBrew]

if you left it at 3 psi, you'd see the regulator pressure rise over time as CO2 comes out of absorbtion and seeks to create an equilibrium pressure in the closed system of the keg/tubing. the issue is you need longer tubing on the serving side of the keg to reduce the pressure at the serving point and reducing the foam, etc. for now though, when you are not using you keg, i.e. from when you go to sleep until the next evening, put the pressure at 12 psi, and then when you go to serve it, drop the pressure to something more like the 3-5psi, repeat.
in time though, get some longer tubing. there are some tips and calculators in the kegging faq section to help you figure out the length needed. there should also be carb charts to show needed PSI at a given temp to keep a certain amount of CO2 in solution.

 

[camiller]

...the issue is you need longer tubing on the serving side of the keg to reduce the pressure at the serving point and reducing the foam,...

or

https://www.homebrewtalk.com/f35/cure-your-short-hose-troubles-100151/