If the density of the electrolyte is not sufficient after checking the density of the electrolyte, it is necessary to finish the concentrated electrolyte in those banks where the density is insufficient. If the bank is full, the electrolyte can be pummbled with acidity (battery-denser), then fill the concentrate and repeat the density check.
If the density of the electrolyte in the battery bank is slightly higher than normal, distilled water is not required. You need to add water only if you deviate from the norm very strongly.