This most certainly depends on your seal design. Generally it is a good idea to contact your manufacturer and discuss your options. Carbon faces are cheap considering the overall equipment costs.
If you are having other issues with the sealing arrangement that is prompting you to question the design then I would recommend posting your issues in this forum or contacting the seal manufacturer and working through the issue. Could be that you have the incorrect design altogether.
As a general guideline, spring forces are very common among seal designs (and even across different seal manufacturers. So I say that to say that your issues likely are not a design problem with working length or spring force.