Review on 🐠 Seachem Matrix Bio Media 250ml: Optimize Aquarium Filtration with Top-Performing Media by Brittany Hamilton

These are approx. 10 mm large pieces of pumice stone, a type of volcanic rock that is quarried in the western states of the United States. If you live in these areas it's very cheap, but if you live in the eastern US shipping can be extremely expensive. I use pumice stone on my succulents (I have a very large collection - hundreds). I order it in 3 gallon bags from General Pumice for about $30 - most of that cost is for shipping, which is included in the price. The same 3 gallon bag is about $6 if I live closer to mine. It's available in a variety of forms - almost like a powder from tiny granules to make your own exfoliating products (just add it to your body or face wash and voila!), as well as many other sizes and shapes. So if you have a lot of tanks, you save a lot of money. I am in no way affiliated with the company; I'm just a grateful and loyal customer. In my opinion, these tiny glasses are a huge plagiarism. This is a great product just overpriced.