String tensions for different tunings

You can use the chart below to work out what gauge of strings to use for different tunings. These strings each have a tension of just under 12kg/27lbs when tuned to the given note. For instance the optimum gauges for DADF#AD tuning would be .059-.040-.029-.022-.018-.014 instead of .056w-.042w-.032w-.024w-.017-.013 from the GHS true mediums that I put on, but the overall tension works out about the same. Try to keep the overall tension below 75kg/165lbs. Excess tension will supress the dymanics and very excessive tension can cause damage.

Here is an excellent string tension calculator that installs on your computer. Or you can use the D'Addario tension chart which also has tensions for flatwound strings. (Flat wound strings have a dull tone on Weissenborn type guitars, so I recommend that you avoid them)