FAQ: Water Care for fish

A conditioner makes tap water safe for fish: it neutralises chlorine and chloramine, and many also bind heavy metals. It is added to new water at every water change, and the manufacturer states the dose on the pack.

Look at the price per litre – on zoogidas.lt you can compare products by price per litre, which shows which bottle is really cheaper. It is also worth checking how much water one dose treats, since products differ in concentration.

Tap water often contains chlorine or chloramine, which irritate fish gills and kill the useful filter bacteria. So it is worth treating new water with a conditioner, even if the local water looks clean and has no smell.

Free chlorine often gasses off from an open container within a day or two, especially if stirred or aerated. Chloramine, however, does not, so if you do not know how your water is disinfected, a conditioner is more reliable.

Both are used to disinfect drinking water and both harm fish. Chlorine evaporates fairly quickly, while chloramine is more stable and releases ammonia when broken down, so the conditioner must also be meant for chloramine, as the manufacturer will state.

Ideally add conditioner to the bucket of new water before pouring it in, so the water is treated beforehand. If you fill straight from a hose, dose for the whole tank volume or as the manufacturer directs, and add it before filling.

Many conditioners tolerate a small overdose, but large amounts can reduce oxygen levels. Increase aeration and watch the fish, and if they gasp at the surface or act strangely, do a partial water change with treated water.

Yes, if you top up with tap water it still contains chlorine or chloramine, so dose the conditioner for the amount added. If you top up with reverse osmosis or distilled water, conditioner is usually not needed.

Many conditioners bind copper, zinc and other heavy metals that can come from old pipes. The pack says so, so if your home has old plumbing choose a product that does this, and run off water that has been sitting in the pipes first.

Some conditioners contain substances that, according to manufacturers, help maintain the fish's natural slime coat and reduce stress during moves or water changes. It is an extra feature; a conditioner's main job remains neutralising chlorine and metals.

Some conditioners temporarily bind ammonia into a less harmful form, which is useful in a new tank or an emergency. This does not remove the cause, and tests may still show ammonia, so a working biological filter and water changes are what matter most.

They are bottled nitrifying bacteria or blends that help a biological filter establish faster. They are used when starting a new tank, after a heavy filter clean or after treatment, when the bacterial colony has suffered.

Dose it as the manufacturer instructs, usually into already conditioned water with the filter running, since the bacteria need flow and surfaces to settle on. They also need food, ammonia, so add fish gradually and test the water.

Some manufacturers say fish can be added quickly with their product, but results vary. The safest approach is to start with a few fish, feed lightly and test ammonia and nitrite regularly for a few weeks before adding more.

In a mature tank with a healthy filter the bacteria multiply on their own, so constant dosing is usually unnecessary. A product helps after water changes, filter cleaning, treatment or when adding many new fish, as the manufacturer directs.

Bacteria starters are live products, so keep them in a cool, dark place, protect them from frost and heat and use them before the expiry date. Some need refrigeration after opening, as the manufacturer states.

Most modern conditioners do not harm bacteria, so both can be used on the same day. Conditioner usually goes in first to neutralise chlorine, and the bacteria starter afterwards, following both manufacturers' directions.

If the cloudiness comes from a bacterial bloom in a new tank, a bacteria starter can help the biological balance settle sooner. If it comes from sand particles or algae it will do little, so find the cause first.

Some medications, especially antibacterial ones, can also harm filter bacteria. After treatment a water change and a dose of bacteria starter are often advised, with careful ammonia and nitrite testing for a few days.

Water prepared ahead has time to reach the tank's temperature, some gases escape and the conditioner has time to work. This matters especially for sensitive fish and shrimp, which are stressed by sudden changes in temperature or parameters.