River Pebbles

Also sold as river rock · pebbles · large gravel · river stones · River pebbles / river rock

River Pebbles is a gravel. It holds no nutrients of its own, which is what decides whether it suits your plants and your shrimp.

At a glance

TypeGravel
NutrientsNone (inert)
GrainCoarse
Effect on pHNeutral
Ammonia when newNone
ShrimpSuits Neocaridina

Before it goes in

  • River Pebbles is a gravel.
  • It is inert: it holds no nutrients of its own. Root feeders such as Cryptocoryne wendtii and Dwarf Hairgrass Mini need root tabs under them.
  • It is pH-neutral: whatever comes out of your tap is what the tank sits at.
  • It releases no ammonia, so livestock can go in as soon as the tank is cycled.
  • Carpeting plants struggle to root in it: the grain is too loose or too large to hold their runners.
  • It is rough on fish that sift the substrate. Something finer suits German Blue Ram and Julii Cory better.
  • It suits Neocaridina, which want harder water than Caridina do.

What kind of substrate is it?

Gravel, coarse grain, holding no nutrients of its own.

Does it change pH?

No — it is inert and leaves your tap water where it is.

Does it leach ammonia?

No, so you are not waiting on it to stop before stocking.

Can I use it on its own?

Yes — River Pebbles is a complete substrate on its own.

Will carpeting plants root in it?

Not easily. Runners struggle to get a hold in it.

What it goes with

Often compared with

River PebblesColored GravelCrushed Lava Rock
TypeGravelGravelGravel
NutrientsNoneNoneNone
pHNeutralNeutralNeutral
GrainCoarse3–6 mm3–12 mm
Leaches ammoniaNoNoNo

More substrates

Sources (4) · checked Sep 2026