Gravel-type filter media that purifies water - Roka Jari

This is a substrate sand for freshwater use (tropical fish, goldfish, turtles).
*A gravel-type filter material that absorbs water impurities and converts them into nutrients for aquatic plants.

It was used for a medaka biotope.
It has been opened.
It was originally in an 8-liter bag, and about half of it was used.
The weight is approximately 4.5 kg.
It was sealed and stored in a bag, but it is stored by an amateur, so please only purchase if you understand this.