SubstrateSource Crushed Aquarium Lava Gravel, Rock - Porous Stone for Natural Planet Fish Tank Decorations and Decor (2 Pounds, Natural Red)

I opted for the black as a base layer under a top layer of ADA aquasoil. It is perfect; looks exactly like the photo. The size of the granules are varied and range from about 2 mm to 6 mm give or take. It is a small bag, so if it's your only substrate you are going to need quite a few bags to fill a 10 gallon (I'm estimating about 6 - 8 bags for a 1.5" depth).

Buying black lava gravel on Amazon is much easier than going to Hawaii and scooping some around a volcano.I bought this as a soil topper for some carnivorous plants. By soil topper, I mean once I pot the plants I put a layer of this on the top so it looks like the entire pot is filled with it. It's an aesthetic choice.The gravel are the size of little 5mm and smaller pebbles. There are no dusty grounded parts to breath in; you get pure gravel.These make great soil toppers, and I suggest looking at other types of gravels and soil decorations to get your desired​ effect. Recommended.

The SubstrateSource Natural Red Lava Gravel is great in my flower pots! It keeps the squirrels and rabbits from getting in my pots to plant their acorns or eat my flowers! The gravel hurts their little feet!!!

I wanted to ensure plenty of space for bacteria in my planted aquarium so put down about an inch of Flourite, then a second layer of this lava gravel (these are about 1/4" in diameter and very rough) to provide spaces for the bacteria, then finally another layer of 2" of Flourite on top. Right before initially filling my tank and starting the filter, I shot a full bottle of Tetra Safe Start (with bacteria) down into the substrate. A month later I have zero ammonia, zero nitrites and only about 5ppm nitrate. It serves the purpose I wanted and I got the results I wanted as well.

Really good substrate. The pieces are larger, maybe 1.5x or 2x. than the black Fluorite substrate. I would purchase more, however, this is expensive substrate, and I ended up mixing equal parts Fluorite and this.

The media could not be loaded.  It works as expected , did my best to rinse before use for my pond

I was meaning to use this for my aquarium as filtration and then maybe add some as substrate. Other reviews on here claimed that the gravel was large, but most of my bag was fairly small varying from pea to rice sized granulars.

Great product! A little dusty, but nothing a bath couldn’t fix. Great for foundations if you want to ad some elevation to a tank.