Gravel is the classic aquarium substrate — easy to clean, endlessly varied in colour, and forgiving for beginners. For a general community tank without fussy bottom feeders, good gravel is often the simplest, most practical choice. This UK guide covers the best aquarium gravels in 2026 and how much you need.

Here are our picks and how to choose.

Gravel vs sand

Gravel is easier to vacuum and lets debris settle on top where a gravel vacuum lifts it away. Sand suits corydoras and diggers better. For a mixed community without delicate barbels, fine gravel (2–5 mm) is the practical all-rounder — see our substrate guide.

Our top picks

Best natural look — fine natural gravel. A fine natural gravel looks understated and is easy to keep clean.

Best for planted tanks — inert gravel over root tabs. An inert aquarium gravel works well for plants when combined with root tabs.

Best coloured gravel — for a specific look. A coloured gravel lets you match a theme — choose smooth, aquarium-safe grades.

How much gravel and grain size

Aim for a bed around 5 cm deep — enough for plant roots and beneficial bacteria. As a rough guide, allow roughly 1 kg of gravel per 4–5 litres of tank for that depth. Choose smooth, rounded grains of 2–5 mm for a community tank; larger grains trap uneaten food and waste. Rinse well before adding.

Frequently asked questions

Is gravel or sand better for an aquarium?

Gravel is easier to clean and forgiving for a general community tank, while sand suits corydoras and other diggers. For a mixed community without delicate bottom feeders, fine gravel is the practical all-rounder.

How much gravel do I need for my aquarium?

Aim for a bed around 5 cm deep — roughly 1 kg of gravel per 4–5 litres of tank volume. That depth supports plant roots and beneficial bacteria.

What size gravel is best for a fish tank?

Smooth, rounded grains of 2–5 mm are best for a community tank. Larger grains trap uneaten food and waste, making the substrate harder to keep clean.

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— Jaqline Smalling, FishForever