Here is a pseudo-code algorithm designed to schedule the nutrient dosage scaling for a hydroponic cultivation facility over a 6-stage crop growth cycle.

1  # Hydroponic nutrient dosing scheduler
2  SET stageName TO ["G1", "G2", "G3", "G4", "G5", "G6"]
3  SET concentrationPercent TO [105, 120, 135, 150, 165, 180]
4  SET inputValid TO False
5
6  # Validate baseline concentration in ppm
7  WHILE (inputValid = False) DO
8      SEND "Enter the baseline concentration in ppm (min 400): " TO DISPLAY
9      RECEIVE baseConcentration FROM (INTEGER) KEYBOARD
10
11     IF (baseConcentration >= 400) THEN
12         SET inputValid TO True
13         SEND "Baseline concentration accepted: " & baseConcentration TO DISPLAY
14     ELSE
15         SEND "Concentration too low" TO DISPLAY
16     END IF
17 END WHILE
18
19 # Calculate scheduled concentrations
20 FOR i FROM 0 TO (LENGTH(stageName) - 1)
21     SET scale TO concentrationPercent[i] / 100
22     SET scheduledDose TO baseConcentration * scale
23     SEND "Stage " & stageName[i] & " dose: " & scheduledDose TO DISPLAY
24 END FOR