How can i find memory leaks in Asp.net website.

as i google it and watching videos on youtube find some of the tool in vs 2015 and based on that data  system.string takes more memory and at starting application it take more then 55mb to load in Process memory(MB) in Diagnostic Tool Vs 2015.

 

i cant understand there is no code wrote on page load but  it takes more memory how i can reduce it to less.

 

 

Thanks Adv