Inert sand

Also known as: Pool filter sand, Silica sand, Play sand (washed), Black diamond blasting sand

Properties

pH effectneutral / inert
KH (carbonate hardness)neutral
GH (general hardness)neutral
Nutrient loadnone
Ammonia release initiallyNo
Particle size0.2 to 0.8 mm
Longevityindefinite
Cost tierlow

How it affects the tank

  • Provides no nutrients to root feeders: heavy-feeding plants (swords, crypts) will yellow and stall without root tabs supplementing
  • Cory catfish, kuhli loaches, and other substrate-sifters thrive on fine sand which lets them filter without scratching their barbels
  • Anaerobic pockets form over time under uniform fine sand; periodic gentle stirring or malaysian trumpet snails prevent hydrogen sulfide buildup
  • Easy to clean with a gravel vacuum held just above the surface; debris lifts off without pulling up the sand itself

Care notes

Rinse aggressively before adding to the tank or expect cloudy water for hours. Pool filter sand is the cheapest reliable option in the US; "black diamond" sandblasting sand is industrial-grade but works fine in freshwater (rinse thoroughly). Avoid play sand without washing; the surfactants kill fish.

Plants that work in inert sand

61 aquarium plants in the catalog list this substrate as compatible.

Sources

Data drawn from: aquatic-plant-central, seriously-fish. Last verified 2026-05-13.

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Further reading