What is substrate in aquariums?
Substrate refers to the layer of material at the bottom of an aquarium, such as gravel, sand, soil, or specialized planted media.
Functions of substrate
- Provides a surface for beneficial bacteria to colonize
- Supports rooted aquatic plants
- Offers hiding and foraging areas for bottom-dwelling fish and invertebrates
- Enhances the aesthetic appeal of the aquarium
Types of substrate
- Gravel: Common for freshwater aquariums; allows good water flow and bacteria growth
- Sand: Soft, suitable for delicate fish like loaches and some cichlids
- Planting soil: Enriched media for live plants, supplies nutrients
- Specialty substrates: Such as crushed coral (raises pH and hardness) or laterite (iron-rich for plants)
Choosing substrate
Consider the species you keep:
- Soft water fish may prefer sand or neutral gravel
- African cichlids often require crushed coral
- Planted tanks benefit from nutrient-rich substrates
Substrate also influences water chemistry, cleaning frequency, and filtration needs.