Aquarium Accessories

A heater is essential for most tropical setups, since tropical fish need a stable water temperature well above typical UK room temperature, and a submersible heater with a thermostat is the standard way to maintain that. Filters do the ongoing work of keeping water clean and supporting the beneficial bacteria that break down fish waste, and choosing one rated for your tank's actual volume, rather than undersized for cost, matters for long-term water quality.

Both heaters and filters are worth checking regularly rather than assumed to be working — a failed heater or a clogged filter can affect fish health quickly, often before it is obvious just from looking at the tank.

Aquarium lighting serves both fish and any live plants in the tank, and the right type and duration depends on what you are keeping — a heavily planted tank generally needs stronger, longer lighting than a simple fish-only setup. Gravel and substrate choices affect both the look of a tank and, for a planted setup, how well plants can root.

Changing or adding substrate is easier to plan properly before a tank is fully stocked, since disturbing gravel around established fish and plants is more disruptive than doing the groundwork early.

Ornaments, caves and artificial or real plants give fish places to hide and explore, which matters for reducing stress in species that are naturally shy or territorial. Real plants add the benefit of helping process some waste products in the water, though they need appropriate lighting and, often, a nutrient-rich substrate to do well.

Whatever décor you choose, checking it is aquarium-safe before adding it to a tank is worth doing, since not everything sold as an ornament elsewhere is safe for a fish tank's chemistry.