$55 · Aquarium reef sand/rocks

I wanted to set up a small reef tank but after I got all the supplies I changed my mind. The sand is the brand “Carib sea” (I paid for it just over 100$) never used as well as the live “dead” rocks (1.6 kg) can be added for an extra 10$. I am not sure how much sand there is. AlI know is that it is a good amount for a 20 gallon tank.(in pictures) If you have any questions please let me know. :)