Independent buying guides for planted aquariums

Planted Aquarium Glossary: 15 Terms Explained

The words that show up in planted aquarium specs, reviews and how-to guides, explained without jargon.

Aqua soil
A nutrient-rich baked clay substrate that feeds rooted plants and softens water.
Related: Best Aqua Soil for Planted Tanks (2026)
Aquascaping
Arranging plants, rock and wood in an aquarium to create a natural-looking underwater landscape.
Canister filter
An external filter under the tank with large media capacity and quiet flow.
Related: Best Canister Filters for Planted Tanks (2026)
Carpeting plant
A low plant that spreads across the substrate, like a lawn. Most need strong light and CO2.
CO2 injection
Adding carbon dioxide to the water for faster, denser plant growth.
Related: Best CO2 Systems for Planted Tanks (2026)
Drop checker
A small glass indicator whose colour shows approximate CO2 concentration.
Related: Best CO2 Drop Checkers for Planted Tanks (2026)
Dutch style
A layout of densely planted stem plants in terraces, with little or no hardscape.
Fishless cycling
Establishing beneficial bacteria with an ammonia source before any fish are added.
Hardscape
The rock and wood that form the structure of a layout.
Related: Best Seiryu Stone for Aquascaping (2026)
Iwagumi
A minimalist Japanese layout style built around stones, often with a single carpeting plant.
Low-iron glass
Glass with less iron content, giving a clearer, less green view.
Related: Best Low-Iron Glass Tanks for Aquascaping (2026)
Nitrogen cycle
Bacteria converting fish waste from toxic ammonia to nitrite and then to less harmful nitrate. A new tank needs weeks to cycle before adding fish.
Related: Best Water Test Kits for Planted Tanks (2026)
PAR
Photosynthetically active radiation, a measure of usable light for plants that is more meaningful than lumens.
Photoperiod
How many hours the light is on each day. Many planted tanks run about 6-8 hours to keep algae in check.
Related: Best Aquarium Light Timers and Controllers (2026)
Water change
Replacing part of the tank water, often weekly, to remove nitrate and excess nutrients.
Related: Best Gravel Vacuums for Planted Tanks (2026)