While aqualandtenerife is more relaxed as compared to Siam Park, the tickets are also based on height restrictions in order to avoid disappointment. You can buy a pass corresponding to your height and age and each ride has a clear denotation of which all age groups they allow.
Adult - 11 or more years old. And/or taller than 1.40m
Child - 5-10 years old. And/or 1.10m to 1.40m
Mini - 3-4 years old. And/or 0.90m to 1.10m
0-2 years old. And/or less than 0.90m: Free admission