FAQ: Grooming for fish

Pond fish need a large, deep net with a long, often telescopic handle. For big fish it is gentler to guide them into a floating bowl or bag than to lift them out of the water in a net.

A marine tank needs constant monitoring of salinity, topping up evaporated water with fresh water, mixing salt water for changes and looking after the protein skimmer. Marine systems react more to change, so care usually takes more precision.

RO water is usually used, with marine aquarium salt added as the pack directs. The water is mixed with a pump and warmed to tank temperature, and the salinity is checked before it goes into the tank.

A refractometer gives the most accurate reading and needs regular calibration with calibration fluid. A floating hydrometer is less accurate and sensitive to bubbles and temperature. Check salinity regularly, not just at water changes.

Regularly empty and wash the collection cup and its neck, because grime reduces the skimmer's efficiency. Clean the pump now and then too. After a water change or dosing, the skimmer may foam unusually for a while.

No, live rock is natural biological filtration home to beneficial bacteria and small organisms, so it is not washed or scrubbed. Debris settling on it can be blown off with a pump or large pipette so the filter catches it.

Marine tanks often use a stronger cleaner matched to the glass thickness, sometimes with interchangeable blades for coralline algae. Marine tanks usually have sand on the bottom, so it is especially important that none gets between the cleaner and the glass.

Coralline algae are hard and chalky, so a sponge will not remove them; you need a scraper with a blade, or a plastic blade for acrylic. It is easier to clean regularly while the spots are small, because they harden over time.

Many tools suit both, but it is better to keep separate sets so organisms and salt are not carried across. Metal parts rust faster in salt water, so choose plastic or marine-safe tools.

Salt water quickly corrodes many metals, and rust can get into the water and harm the animals. Rinse tools in fresh water and dry them after every use, and replace any that start to rust.

Change the water and clean the filter a few days beforehand rather than on the last day, so any problems show up in time. Put the lights on a timer and arrange feeding: an automatic feeder or help from a neighbour.

Healthy adult fish in an established tank usually cope with a few days, some longer, without much harm, but fry and very small fish cannot. For a longer trip arrange feeding; overfeeding is more dangerous for fish than a short fast.

An automatic feeder is handy for holidays or an irregular work schedule. Test it for a few days before you leave to make sure the portion is right and the food does not get damp and clump from the humidity.

Prepare daily portions in separate boxes or a pill organiser and write down clearly what to do and when. Ask them to check the filter and temperature daily and to feed only the prepared portions, because overfeeding is a common holiday problem.

Oxygen and warmth matter most: if the outage is long, use a battery air pump, wrap the tank in a blanket in cold weather and do not feed the fish. When power returns check the filter, and after a long stop rinse it in tank water.

Catch the fish into bags or containers of tank water and keep the filter media wet in tank water so the bacteria survive. Drain the water, take out the substrate and decorations, then carry the tank empty.

Carry fish in bags or sealed containers of tank water with air, in the dark, inside a cool box or carton so the water does not cool or heat too quickly. Do not feed them the day before so the water stays cleaner.

No. A full tank is very heavy, and moving the water and gravel puts stress on the seams, so they can start leaking or the glass can crack. Drain the water and remove the substrate and decorations before moving it.

If you have cuts or scratches on your hands, long aquarium gloves are worthwhile, because bacteria in the water can enter through wounds. Either way, wash your hands with soap after working in the tank.

Wash your hands without scented soap and rinse well so no lotion, perfume, insect repellent or cleaning product is left on the skin. These substances can harm fish and invertebrates in the water.