Indeed, there is a problem here if we have a model with more than 25 additional tracers. None of the models that we distribute have that many tracers except EcoSim. However, we do not expect any application that requires different boundary conditions for each of EcoSim passive tracers. In this case, we use the compact specification for LBC. For example, for East-West periodic application, we will have:
! W S E N
! e o a o
! s u s r
! t t t t
! h h
!
! 1 2 3 4
LBC(isTvar) == Per Clo Per Clo ! idbio(:), compact
ROMS will internally assigns the same boundary conditions for all passive tracer since we just specified a single line in the standard input script.
I followed your recommendation and I increased the value of Cval to 200.