Hey Kleinschmidt,
after examining your website with a speed test tool (results here, scroll down the page for a breakdown by individual files), I can recommend optimizing the images that make up the gallery slides in order to reduce their size (e.g. downsampling or – preferrable – converting into jpg and reuploading), since the page is quite large in size (8.3 MB, compared to e.g. Ikebana theme demo, which is only 3.8 MB), and several images are almost 1 MB in size each (e.g. this one and this one).
Sincerely,
Andrew / Satori Studio