

Gravel
Aqua Natural Midnight Pearl Bio-Substrate, 5 lb
4.9 · 31 reviews
$12.99
Sold and shipped by the online store behind the button; bags go back the same way
The 2–4 mm Midnight Pearl pebble, shipped wet with live nitrifying bacteria. Gravel's big surface area gives the colony plenty of room.
Product highlights
- 2–4 mm pebble
- Live bacteria blend
- Brown, black and gold tones
- Single bag or 2-pack
- Primary floor or mixer
Bag sizes and prices
| Option | Price |
|---|---|
| 5 lb wet bag | $12.99 |
| 5 lb wet bag, 2-pack | $23.81 |
Specifications
| Base | Midnight Pearl gravel |
|---|---|
| Grain | 2–4 mm |
| Bag | 5 lb, wet |
| Packs | 1 or 2 |
Good to know
Gravel bio-substrates suit tanks with digging fish better than sand ones — the pebble doesn't cloud.
Orders and returns
The order, shipping and any return are handled by the store that sells it. See how orders travel.
Reviews by real customers
Small stone size gravel
The gravel looks good and not as big as normal aquarium gravel that works well for the kuhlii loaches to dig in. When I put the gravel into the aquarium it did make the water cloudy but that cleared up quickly.
Cat · June 2026Safe for betas
Fish has been in the tank for a week now he's thriving. I have live plants in there and they seem to be doing great as well.
Tasha · November 2025Great Substrate for Oranda goldfish
I bought this substrate because I researched what stone, sand, pebble was the best for Oranda goldfish. This type of rock is best and the fact that it comes pretreated with good bacteria was a huge bonus
CrystalB · June 2023
Cycles instantly
Most reviewed
1:4 mixer
2-pack too