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The Complete Aquarism Glossary

Decode the jargon. Everything you need to know about fish keeping, from "Ammonia Spikes" to "Zebra Danios".

All Terms
Anatomy Aquarium Problems Equipment & Hardware Filtration & Water Flow Physiology Tank Setup Water Parameters

P

pH
Water Parameters
pH measures how acidic or alkaline aquarium water is on a 0–14 scale and directly affects fish health, stress levels, and biological filtration.
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Powerhead
Equipment & Hardware
A powerhead is a submersible pump that increases water movement, circulation, and oxygen distribution in aquariums.
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S

Sponge Filter
Filtration & Water Flow
A sponge filter provides gentle mechanical and biological filtration by drawing water through a porous sponge, ideal for small tanks and fry.
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Substrate
Tank Setup
Substrate is the material covering the bottom of an aquarium, providing habitat for beneficial bacteria, plants, and bottom-dwelling fish.
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Surface Breathing
Physiology
Surface breathing is when fish breathe at the water’s surface due to low oxygen stress or as a normal adaptation in some species.
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Swim Bladder
Anatomy
The swim bladder is an internal gas-filled organ that helps fish control buoyancy and maintain stability in the water column.
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T

Thermostat
Equipment & Hardware
A thermostat regulates aquarium heaters by turning them on or off to keep water temperature stable and safe.
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U

UV Sterilizer
Equipment & Hardware
A UV sterilizer uses ultraviolet light to reduce free-floating algae, bacteria, and parasites in aquarium water.
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