BiOrb Aquarium Care

BiOrb Aquarium Care

Set up the aquarium following the step by step instructions in the Activation Guide. Making sure the water preparation chemicals have been added leave the aquarium for at least 24 hours with the air pump running before introducing the first fish.

Plants can be added at this stage.

You must resist the temptation to fill your aquarium with fish straight away. One small goldfish (1“ to 1.5”) or three small shoaling fish (such as white cloud mountain minnows) can be introduced.

Wait at least 28 days before adding any more fish.

A gap of 28 days should be left between each addition of fish. Never add more than one goldfish or three small shoaling fish at a time. Buying too many fish at a time can kill the fish or at least make them very ill.

If transferring fish from an existing aquarium to a new aquarium the fish must be moved over gradually as described above.

Always feed sparingly - overfeeding is the biggest cause of aquarium problems.

Measure out food carefully, do not use a ‘pinch’. There are no exact rules for feeding fish but as a rough guide:

.1-3 cm shoaling fish (minnows, danios etc)

.3-4 tropical micro-pellets or 1-2 tropical flakes each per day.

.2-5 cm goldfish

.2-4 small pellets each per day

Establishing Your New biOrb Fish Tank

There are good bacteria and bad bacteria. Aquariums use good bacteria to eat toxic fish waste. The rocks at the base of the aquarium will be home to these good bacteria.
The bacteria need to grow into a good sized population, become ‘established’, so that they can keep the water clean of fish waste.Filter bacteria need food (fish waste) so that they can multiply. To do their job, the bacteria also need a constant supply of oxygenated water. This is provided by the air pump which must be left running 24 hours a day.
When the fish goes to the toilet ammonia is produced. Ammonia is deadly to fish. The bacteria convert the toxic ammonia into a safer substance called nitrate. For every small goldfish added it takes around four weeks for enough bacteria to multiply for that fish. This is why fish must be added at a rate of one every four weeks.
It is important that the biological filter is given time to become established. A few bacteria are introduced to the aquarium with the water preparation chemicals and 24 hours later one small goldfish can be added.

Start With One Small Goldfish

When the new fish goes to the toilet filter bacteria start to multiply to catch up with the amount of work they have to do. The fish should be fed very sparingly. After about 28 days there should be just enough bacteria to cope with all the waste from that one fish. The water quality should then be good and the aquarium is ready for one new fish. The process will happen with every new fish.

Adding More Than One Goldfish

If more than one goldfish is added at one time then there will suddenly be too much waste in the water. Filter bacteria cannot multiply quickly enough and so struggle to clear up all he waste. The extra waste will build up and pollute the water. The polluted water can be clear, cloudy or eventually brown or green with algae growth.This is very unpleasant for your fish, breathing can become difficult and they may die.

Choosing Your Fish

There is a good choice of cold water fish available, tropical fish can be kept if an aquarium heater is fitted inside the aquarium. The suitability of fish depends largely on their adult size, behaviour and requirements. Hardy varieties of fantail goldfish are a good choice for Reef One aquariums. Avoid fancier varieties such as celestials, bubble eyes and pearl scales which can be harder to care for and Oranda which can grow too big. Common goldfish are fast swimming and boisterous, they shouldn’t really be mixed with fantail goldfish, they are better suited to very large aquariums or ponds.
Common goldfish, such as comets and shubunkins usually have a single flat tail and cigar shaped bodies. Fantail goldfish have long tails which look like two tails joined together. Their bodies are shorter and rounder.

Smaller cold water fish such as white cloud mountain minnows are very hardy fish, a shoal of six (three at a time) can be mixed with fantail goldfish.
Small ‘cool water’ fish can be kept providing you use an aquarium thermometer to check that the temperature in the aquarium does not drop below 190C (170C at night). These type of fish include danios, some guppies and platys amongst others. These shouldn’t be mixed with goldfish.

Do not keep bottom feeders, such as common pleco, loach or catfish in Reef One aquariums. The ceramic media used for biological filtration in Reef One aquariums can be damaging to their delicate faces as they root about in the rocks. Many of these species also grow very large.

There is a massive variety of small tropical fish which can be mixed together or kept as a large shoal of one species. As with any pet, you should do a little research into your chosen fish before buying from the wealth fish books and web sites devoted to fish keeping.

Check that the fish you buy will be compatible with your existing fish or the fish you plan to have. They should be healthy and alert, scales should be smooth and not damaged or infected.

With fantail goldfish in particular check that they are swimming straight (not sideways or up-side down) and that their tails are not at an abnormal angle. Don’t be afraid to reject a fish that you do not think is healthy, if you are not happy with it don’t buy it.


Moving to a new aquarium is a very stressful experience for fish. Sometimes this is all too much for them and they do not survive. By planning your purchase and taking the best care possible you can minimise this stress to give your new fish a better chance of enjoying their new home.

Always make sure that the fish you buy can be taken straight home to your aquarium. When traveling, keep the fish steady, secure, out of direct sunlight and heat. Covering the fish bag with a paper bag or box will help to reduce stress to the fish and help tropical fish maintain their temperature.
Once home, open the bag and roll down the sides like a sock. To equalise the temperature in the bag and the aquarium, float the open bag on the surface for 30 minutes.

Carefully release the fish into the aquarium by slowly tipping the bag and allowing the fish to swim out. Try to minimise the amount of water from the bag entering the aquarium. Leave the aquarium light switched off and do not feed until at least the next day.


Good quality prepared fish foods provide a well balanced diet, however, fish do relish eating a variety of foods. Fantail goldfish in particular will benefit from a varied diet.

Daphnia, brine shrimp and bloodworm or a mixture are enjoyed by most fish and can be purchased either live, in frozen packets or in vitamin enriched jelly. Only buy live food from a reputable source, frozen foods should be defrosted before being fed.


Eating flakes requires the fish to spend a lot of time at the water surface increasing the amount of air which could be swallowed by the fish. It is mainly for this reason that pellets are thought to be better for goldfish, for whom swallowing air can contribute to swim bladder problems.


Chunks of cucumber, courgette, blanched lettuce leaves and peeled peas are usually well received by goldfish and some tropical fish. Leave in the aquarium for 24-48 hours and take out before they go bad. Plant based fish foods, such as algae wafers, are also a good addition to the diet. All these foods should be in addition to a good quality fish pellet or flake.


Fish, especially goldfish, are programmed to gobble up everything they can, far more than they need in-fact. As a consequence it is very easy to overfeed fish.

Everything a fish eats is excreted into the water so the more the fish eats the higher the risk of pollution becomes. A well fed aquarium is more likely to develop poor water quality, sick fish and algae problems.

Gold fish and tropical fish have different nutritional requirements, use an appropriate food for each. Any food left in the aquarium after two minutes should be removed.

Measure out food carefully, do not use a ‘pinch’. There are no exact rules for feeding fish but as a rough guide:

.1-3 cm shoaling fish (minnows, danios etc)

.3-4 tropical micro-pellets or 1-2 tropical flakes each per day.

.2-5 cm goldfish

.2-4 small pellets each per day.

.5-10 cm goldfish

.4-6 small pellets each per day.


If you will be away from your fish, it is important that someone checks the air pump is working and that if a fish dies it is removed from the aquarium straight away. Either of these situations could kill your fish before your return. A spare air pump should be left with instructions in case the existing pump fails.

Fish are live animals and so should be checked every day, even though they will probably not need feeding unless you are away for more than 10 days.

Holiday blocks of fish food can be used but there is a danger that if uneaten these foods could pollute the water. A well meaning but inexperienced feeder could do more harm than good by overfeeding fish while you are away. In most cases it is preferable to let the fish go hungry although certain fish may require more regular feeding.

If you do get someone to feed your fish measure out the correct amount of food and ask for this to be fed over the time that you are away.


If a fish dies you should remove it from the aquarium immediately, if left in the aquarium it will badly pollute the water. You should try to establish why the fish died. Make note of anything which is abnormal. Take a sample of your aquarium water to a good aquatics retailer for testing and advice. It is often useful to try matching symptoms with pictures in a fish care book.


Good aquarium husbandry and fish selection will help to prevent disease. Chronic stress can suppress the fish’s ability to fight disease, the most common causes are water quality problems.

Most medications include very clear instructions on diagnosis and treatment, some also offer a help line.



The swim bladder is a gas filled sack inside most fish which controls their buoyancy in the water. Problems with the swim bladder cause fish difficulty in swimming, and is common with fantail goldfish. Bacteria infections and air swallowing are thought to be common causes of swim bladder problems. Feeding a varied diet can help in prevention.

Swim bladder problems are not usually life threatening, however it can be a symptom of a more serious disease. If a fish is suffering badly for more than a day or two it may be worth using a swim bladder medication.

Some fish suffer regular bouts of swim bladder; the fish is uncomfortable but soon recovers. If, however, a fish constantly suffers with swim bladder to the extent that it affects the quality of life, and nothing helps, you may wish to consider seeking advice from a vet.


It is unlikely that fish get lonely or bored, however, animals do benefit from having a more challenging lifestyle. Fish must be compatible with each other and goldfish should be of a similar size when introduced to each other.

Shoaling fishes like minnows need to live in a shoal. They can feel under threat of predation if they do not have the security of living in a group.


Water tests should be routine for every fish keeper. You can purchase a test kit to use at home or take a sample along to a good aquatics shop. It is important to at least test for:

Ammonia (from fish waste) level is likely to be quite high every time a fish is added. Once the aquarium is established, ammonia readings should be zero.

Like ammonia the level is likely to be high when fish are added but once the aquarium is established should be zero. Subsequent high readings of ammonia or nitrite indicates that biological filtration has broken down or that the fish have been overfed.

Nitrate should be used as an indicator of your aquarium’s hygiene. It shouldn’t be more than 50 ppm above the level in your tap water. If it is higher then you should increase the frequency of your partial water changes.

pH is the measure of acidity and alkalinity of the aquarium water. pH 7 is neutral, 1-7 is acid, 7-12 is alkaline. Most cold water fish prefer a pH of 7.5-8.0, tropical fish vary in their requirements. Even tiny changes in pH are very stressful to fish.

Why do I have to change the filter cartridge so often?

The filter cartridge works like a waste bin, trapping solid particles and absorbing some nitrate and phosphate from the water. After a time the this will become ‘full’, and unable to absorb any more and may release pollutants, causing the water quality to deteriorate.

By regularly changing the filter cartridge Everything it has absorbed is removed from the biOrb, just like taking your household waste bin out to be collected. For optimum filtration the filter cartridge should be replaced every 1-2 months.

Can I wash the sponge?

If the sponge gets dirty before a change is due it can be washed. However the chemicals in the filter cartridge only remain ‘active’ for a limited period, after this period toxins, which have been absorbed, may be released back into the water. Therefore the cartridge should be replaced.

Does the filter contain activated carbon or Zeolite?

The filter cartridge contains activated carbon and resins which should be removed before using aquarium medications. Leave the sponge in the cartridge to continue trapping dirt and replace with a new cartridge when the treatment period is over.

Do I have to keep the ceramic media provided?

The ceramic media provide essential biological filtration.

It is your fish’s toilet, bacteria will colonise the media and consume toxic fish waste making the water safer for your fish to live in. Without this water would become very polluted very quickly.

Can I put aquarium gravel in the biOrb?

We strongly advise against putting gravel, sand or small stones in the biOrb. Gravel is likely to reduce filtration and may become lodged in the filter cartridge casing.

Will changing the cartridge kill the filter bacteria?

No. The filter cartridge provides mechanical and chemical filtration. Biological filtration is provided by the ceramic media therefore is not affected by the filter cartridge.

Why do I have to keep the biOrb out of sunlight?

All round fish bowls have a magnifying effect. While this adds to the appeal of them, if placed in direct sunlight they produce a focal point of light that can scorch/burn materials and possibly cause fire. Direct or strong daylight can cause excessive algae growth and cause temperature fluctuations within the aquarium making life uncomfortable for fish.

Can a heater be added to the biOrb to make it tropical?

A 50 watt heater can be added to the biOrb with the aid of a Reef One heater stand. There is a snap out section in the light unit into which the cable can rest.

Can I use a longer airline?

Anything longer than 3-5 metres will require a larger air pump. Always attach the new airline to the pump end of the existing airline, not the biOrb end. Trim the end of the tube you detach from the pump and use either a straight airline connecter, or better still a one way valve.

Why am I getting fewer bubbles?

If you have noticed that there are fewer bubbles you may need to change the air stone. Alternatively if you have just changed the filter cartridge, air from the sponge may be trapped inside the cartridge. Twist the bubble tube and lift one side of the filter cartridge slightly to allow air to escape. You may need to do this a few times.

What is the air stone?

The air stone is the small white cylinder at the base of the biOrb. The air stone breaks up the air being forced through it into a stream of bubbles.

My filter appears to be filling with air?

This can be a sign that the air stone has become blocked and caused a small air leak. Removing the air stone will solve this and start the filter working again. Without the air stone the filter will be slightly noisy so we recommend putting a new one in as soon as possible.

My light bulb has stopped working?

Light bulbs do wear out. The special halogen bulb used in our light unit should last at least 1600 hours. This can easily be replaced following the instructions included with the light unit. biOrb light bulb

What happens if there is a power cut?

A power cut will interrupt the supply of oxygen into the biOrb. Without oxygen for long periods filter bacteria will start to die and the water may become polluted. Fish may also experience difficulty breathing, particularly at night when oxygen levels naturally drop and live plants take their share of oxygen too.

It is advisable to test the water after a noticeable power cut to see if the water has become polluted, so that remedial action can be taken. If long term power failure occurs it is essential that the air pump is raised well above the biOrb water level as per air pump instructions.

Got a question not answered here? Get in touch by phone, fax or email and we will be happy to deal with your query.