Equipment
AquariumHQ explains what a category of equipment does and where it fits. It does not tell you which product to buy.
Why there are no product recommendations here
Product ranking is a different business with different incentives, and mixing the two quietly corrupts the first. There are no brands, no models, no prices and no affiliate links anywhere in this section, and the data model has no field for any of them.
Aquarium (2)
- Quarantine tankA simple bare tank with a sponge filter and heater, used to hold new arrivals for observation and to treat sick fish away from the display tank.
- Lid or coverA cover that stops fish jumping out, reduces evaporation, and keeps dust and objects out of the water. For many species it is not optional.
Filtration (4)
- Sponge filterAn air pump draws water through a foam block, which provides both mechanical trapping and a large biological surface. Cheap, gentle, and impossible for fry or shrimp to be drawn into.
- Hang-on-back filterA pump lifts water into a box hanging on the tank rim, through media, and returns it over a weir. Convenient, easy to service, and the most common filter on small and medium tanks.
- Canister filterA sealed external canister containing several litres of media, plumbed to the tank with inlet and outlet pipes. The highest capacity option and the quietest.
- Internal filterA submersible pump-and-sponge unit that sits inside the tank. Simple, cheap and space-efficient in the room but not in the tank.
Filter media (2)
- Filter mediaThe material inside the filter. Coarse sponge traps large debris, fine floss polishes, ceramic or plastic bio-media houses bacteria, and chemical media targets specific dissolved substances.
- Activated carbonA highly porous adsorbent that removes dissolved organics, tannins, odours and medication. It does nothing for ammonia, nitrite or nitrate, and it exhausts within weeks.
Heating (1)
Lighting (1)
Aeration (1)
Circulation (2)
CO₂ (2)
- CO₂ systemEquipment that dissolves carbon dioxide into the water for plant growth: a gas source, a regulator, a diffuser and, ideally, a solenoid on a timer.
- Drop checkerA small glass vessel holding a 4 °dKH reference solution with pH indicator. Its colour reports the CO₂ concentration that has equilibrated into that known water.
Testing (1)
Substrate (1)
Maintenance (1)
Plant equipment (1)
Measurement (3)
- ThermometerAn independent check on what the heater is actually doing. The single cheapest piece of insurance in the hobby.
- TDS meterA conductivity meter that multiplies its reading by a conversion factor to report total dissolved solids. Useful for tracking change; useless for identifying which ions are present.
- Reverse osmosis unitA membrane filtration system that produces near-pure water, used to dilute hard tap water down to a target hardness — after which it must be remineralised.