hmin of parent and child grids

[redhat007]

Dear
in refinement case, is it possible that child gird's hmin be less than parent grid's hmin?
That is because, in my test bathymetry data in child grid (near the coast) has been replaced with better data (which contains values less than parent' hmin) and then their averages have been put into parent grid.
For example hmin in parent and child grids are 7m and 2 m, respectively. Should i change hmin of parent grid to values equal or less that child ' hmin, manually? Or there is no problem that parent's hmin be greater that child's hmin.
i have no idea about what is correct.
thanks for any reply

[redhat007]

sorry for asking again.
is it possible(or reasonable)to change refined grid's hmin to value less than coarse grid's hmin?