SCURETTO 990WT Walk Through
90 x 90/160 x H 215 cm

If there is a need to reduce the number of polygons you need to select all elements with id 2 in the water object in the material section and delete them.

Who works in V-Ray version lower than 3.1 be careful in the materials in the BRDF section there is Microfaset GTR (GGX) if your version is older than 3.1 then the BRDF field will be empty. Choose Blinn Phong or Ward – which is preferable for you

For Corona render it is recommended to install at least version 1.5 as the glossiness of the materials is adjusted with PBR in mind.