Terrain as platform for endless runner game will be right or not ?

I have made 3d endless runner game . At first I have created 2 pieces of terrain for player to move on, but when I run my game the size of RAM it take increase by passing the time, I really don’t know why? When I use something else than terrain as platform for example a cube or other mesh objects, there is no problem of memory .

Terrains are realy heavy performance wise and if you are targeting mobile devices, you should consider converting your terrains to meshes.
Just make meshes and dont use terrains or if you already created terrains and want to use them as meshes you can check out a plugin i made to convert Terrains to meshes

Thanks a lot . I really think that there are still humans that think humanly and always try to help others. Thanks a lot again but I promise I will buy your plugin whenever I have a credit card. @ CrywolfDigital