What is the smallest size aquarium gravel out there? I want to use something smaller than pea size for my cichlid small tank. I'm l little too nervous about sand at this point.

I seen it as small as 1/8" but it doesn't have be aquarium gravel you can buy a lot of suitable substates at the local hardware store or garden center if you look around, but most of my tanks are bare bottom


Rick

I've read it has to be inert, I'm assuming this means having no chemicals so as not affect the PH.

"Inert" also means that the substrate irself does not react with the water, which is why limestone is generally a material to avoid. Limestone leaches minerals into the water and affects the water chemistry. If you are unsure about a rock or substrate (sand for example), pour a bit of vinegar on it. If it fizzes, then you know its gonna leach minerals into the water. In addition to pH, rocks/substrate that leach minerals into the water often effect hardness and alkalinity.

I like well-washed play sand. You'll get mixed reactions as to the suitability of various sands from the local hardware or department store. The big thing ya have to be aware of if you choose to use any sand not specifically intended for aquarium use is that it should not have any kind of additive. Play sand is generally safe, as the intended use limits the potential additives since it has to be safe for use by children. That does not mean that it won't contain limestone or other rock that could leach into the water.

WYite

I've used random things for substrate and decorations from my local craft store as well. Much like play sand if it's certified non-toxic (for kids) and won't dissolve in water odds are pretty good it's fish safe.

If you're looking for a bit bigger than sand, glass beads could work. I got a big cheap mixed bag once, and used them for a 5g tank and it looked pretty nice.