I got lazy and didn't clean my aquarium sand, what bad can happen?

This is what I used [gravel link on Amazon](https://www.amazon.fr/gp/product/B0778SV6MZ/ref=as_li_tl?ie=UTF8&camp=1642&creative=6746&creativeASIN=B0778SV6MZ&linkCode=as2&tag=aventureaquar-21&linkId=2f3f283ede469c3162c6748c7804c6a7).

So far everything is good.