FAQ: Grooming for fish

Unplug the filter, heater and lights before putting your hands in the water. A residual-current device adds safety, and cables should have a drip loop so water cannot run down to the socket.

It is a dip in the cable below the level of the socket: the cable hangs down and only then rises to the plug. If water runs along the cable, it drips off at the lowest point instead of reaching the socket or power strip.

Yes, children enjoy feeding fish or cleaning the glass, but an adult should control the portions so the fish are not overfed. Keep water treatments and medications out of children's reach, and everyone should wash their hands afterwards.

Common mistakes: rinsing the filter in tap water, changing a lot of water or all the filter media at once, using soap or household chemicals, adding unconditioned or different-temperature water, and cleaning everything on the same day.

Detergents are hard to rinse off, and even small residues damage fish gills and slime coats and harm invertebrates. Hot water and a brush are enough for the tank and equipment, with vinegar for limescale in an empty tank.

Many aquarists spread these jobs over different days or weeks so they do not remove too many beneficial bacteria or change too much at once. A gentle rinse of the filter in tank water during a change usually does no harm in an established tank.

Yes. Cleaning the filter, substrate and decorations too often and too thoroughly removes too many beneficial bacteria and upsets the tank's balance. An aquarium needs regular, moderate care, not sterility.

Brief restlessness can come from the disturbance itself, hands in the water and moved decorations. If the fish gasp at the surface, dart about or hide for a long time, check the new water temperature, whether conditioner was added and the water parameters.

Not for routine maintenance. Catching and moving fish stresses them more than a water change or glass cleaning, and the water in a temporary container changes quickly. Fish are only removed when moving the tank or doing a big rebuild.

Plants often carry tiny snails or their eggs that go unnoticed. It is worth inspecting and rinsing plants before planting. A few snails are useful because they eat leftovers, while a population explosion usually points to overfeeding.

Feed less so the snails have less food and pick them out regularly by hand or with tweezers. If you put a piece of vegetable or a snail trap in the tank in the evening, the snails gathered on it are easy to remove in the morning.

Feed only what the fish eat within a few minutes and siphon or net out the rest. A feeding ring helps with floating food and a feeding dish with sinking food, because the food stays in one place and is easy to remove.

Yes, especially when feeding bottom fish and shrimp sinking or frozen food. The food does not disappear between the gravel, so leftovers are easy to collect after feeding and the substrate stays cleaner.

Secure the cables with clips or ties, raise the power strip off the floor and keep it away from the filter and hoses. Label which plug belongs to which device so you can quickly switch off the right equipment when cleaning.

Wipe up spills straight away, because moisture eventually swells particleboard and ruins the cabinet. Lay a towel down when cleaning the tank, and put a tray or mat under an external filter so you can spot a leak.

Surprisingly, a medium tank of roughly 60–100 litres is easier to look after than a small one. In a larger volume of water the temperature and parameters change more slowly, so mistakes harm the fish less quickly.

Yes. More fish means more waste, so the filter clogs faster, nitrates and algae build up and water must be changed more often. Do not overstock the tank, and allow for the adult size of the fish.

Every few weeks switch off the light and wipe dust, condensation and limescale off its cover with a damp cloth. A dirty light gives plants less light. Keep water away from the connectors.

Fluorescent tubes weaken over time even though you barely notice by eye, so they are often replaced about once a year or as the maker advises. LED lights last much longer, but their output also slowly drops over the years.

Compare it with another reliable thermometer placed in the same spot. Stick-on strip thermometers on the outside of the glass are only approximate because room air affects them. A wrong thermometer can hide a faulty heater.