The Tank:- Choosing the right size tank will depend on what species you want to keep, how many seahorses and whether you wish to breed them. A minimum depth of 30 cm is recommended, as tank depth is more important than width. Don’t forget to check the recommended stocking densities.

Lighting:-Aquariums function better with light, natural light can work well in some situations but you can enhance your tank by lighting with fluorescent tubing. It is however important to purchase special tubes that either provide daylight conditions or tubes that intensify Seahorse colours. Conditions vary if you wish to add live plants to your tanks. Fluorescent tubes specifically for marine environments are available and the choice is yours.

Aeration:-All living things in your aquarium need oxygen to live. So aeration is an important requirement. Seahorses like oxygen levels to be near saturation, an airpump is necessary to provide this. Air pumps do as they suggest pump air into the tank, but there is an added bonus, as these pumps create bubbles, which flow to the surface agitating and circulating the water. Air powered filters provide aeration as well as filtration. Air stones should not be used as larger bubbles are recommended. This minimises the risk of bubbles getting into the brood pouch of Seahorses during the courtship dance.

Tank Decorations:-A variety of mediums can be used as bottom substrate for your tank, gravel, sand, crushed coral/shell etc. All of these will become “live” as beneficial bacteria will cling to them during the Nitrogen cycle.

Seahorses do not spend all day swimming and will need “hitching posts”. You can add live or fake plants the choice is yours. Seahorses enjoy lots of little nooks and crannies to hunt around or hitch to. Ensure there are no sharp edges or points that may damage to the seahorses fragile skin.

Why do you need to filter your tank? When you set up your tank you will start with beautiful clean water. But you have to keep it that way. There are contaminants such as ammonia, nitrite and nitrate that can’t be seen and these are deadly to your seahorses, especially in high concentrations. The only way to keep these under control is to continuously filter your tank.

Your seahorse tank will need some form of Biological Filtration.

Biological filtration uses a process known as the nitrogen cycle - the removal of nitrogenous wastes by bacterial action. Basically this process uses beneficial bacteria to convert toxins like ammonia into relatively harmless substances. All marine tanks need biological filtration. Bio-filters used with some form of mechanical filtration are the best form of filtration for a seahorse tank.

There are quite a few forms of filters that can be used, do some research into the various kinds and choose the one that suits your needs best.

Like all fish, seahorses create ammonia as a waste product of digestion. It is also produced through the decay of plant matter and uneaten food from overfeeding. Ammonia is deadly to all fish.

Invisible toxins like ammonia and nitrite are transformed into the relatively harmless substance nitrate by the “Nitrifying” bacteria (Nitrosomonas and Nitrobacter respectively) in a process known as the nitrogen cycle.

These aerobic bacteria (require oxygen to live) attach to surfaces such as gravel, glass, rocks, filter panels, sand and filter media. The more surface area you have the more bacteria can grow.

The Nitrogen cycle can take 3-6 weeks to be working efficiently. It is important to monitor the ammonia, nitrite and nitrate levels during this cycle period.

You will need to test your aquarium every couple of days. Your ammonia levels will be the first to rise, as the first nitrifying bacteria starts acting, you will notice what is called a nitrite spike with high nitrite levels, followed by high nitrate levels.

You will notice these levels lessen and by the fourth or fifth week you should be getting nil ammonia readings (0.0 ppm), nil nitrite levels (0.0 ppm) and readings of > 40 ppm of nitrates.

Once the above readings have been achieved, your bio-filter is active and you can introduce your seahorses to the tank. Without the biological breakdown of toxins the seahorses will literally poison themselves. These beneficial bacteria will grow as your tank ages.

You can start a biological filter going by adding products containing these bacteria, but you should not use fish to start your bio filter. Products like Bio-start or similar are available. Ensure you read all directions carefully.

If you can access clean seawater from the ocean, then do so. Ensure that the place you are collecting from has no sewerage, stormwater or river outlets nearby and there are no visible algae blooms. Some aquarium shops sell ocean sourced water for convenience.

Making Sea Water:-Most aquarium shops sell marine water additives. Do a bit of research into the various brands available. Read all the directions carefully and follow them. Always start with de-chlorinated fresh water in your clean bucket and DO NOT use household salt.

Water Quality Monitoring:-There are six main tests you need to perform on your tank on a weekly basis. A small chart or record book helps you to notice fluctuations. It is best to test your water quality at the same time of day. For example if you perform your first tests late afternoon/night time, ensure future testing is not done in the morning, things like light can have an effect on your test results. It is not important what time of day you do your testing, but keep the time of test consistent.

Test Kits:-For most of your water tests the simplest and most economical test kit is a colormetrics salt-water test kit. These kits work by taking a small sample of your tank water, mixing with special reagents (either in drop or tablet form) and after a time period, colour matching to a colour chart. You will need to read all instructions carefully and ensure you follow them correctly. They must be salt water test kits.

Temperature:-Seahorses must be kept at the recommended optimum keeping temperature.

An aquarium thermometer provides an easy, cheap effective form of measurement. For ease a submersible or floating thermometer can be added to the tank to see at a glance.

Salinity:-The main cause of change in this reading is evaporation e.g. using a heater and not having a lid or hood on your aquarium. It is the water that evaporates not the salt.

The cheapest method of measurement is via a hydrometer. This measures the specific gravity of your water. Always keep your seahorses as close as possible to the optimum salinity requirements. When your salinity is too high you need to add de-chlorinated fresh water, if you add seawater you will not change the salinity. Only ever make small adjustments (<10% of total volume).

pH (acidity or alkalinity of water):-Seahorse excretions, decaying food etc., cause changes in your pH. The optimum pH of seawater is 8.2 Colormetric test kits are probably the easiest and cheapest. High pH is alkaline and low pH is acidic. Never change the pH by more than 0.2 in any 24-hour period.

Readings of between 8.1 and 8.3 don’t cause major stress, but if your pH is changing there may be a reason. Test for Carbonate Hardness (kH) this could be your problem.

Ammonia (NH₃ /NH₄⁺ ):- Ammonia is the toxic waste produced by your seahorses when they excrete. This is a soluble toxin, you can’t see it, although your water will look clear, it could be poisoning your seahorse. This is a MUST test EVERY week. Your reading should be 0.0 ppm at every test. The best way to reduce ammonia levels is to do 20-50% water change to your tank.

Nitrite (NO₂^- ):-Nitrite levels in an established aquarium should always remain below 0.25 ppm.

Nitrite spikes (or high readings) as they are commonly called, occur when you are establishing your biological filter as part of the nitrogen cycle.

If you are experiencing levels of nitrite you may have damaged your bacteria that live on your filter medium (gravel, glass, coral, sand bio-balls etc). To reduce nitrite levels a 20% - 50% water change is recommended.

Nitrate (NO₃^- ):-Nitrate is the waste material produced by the second group of nitrifying bacteria after converting the nitrites. Marine tanks should have levels of <30 ppm. To reduce levels of nitrates in your water perform 20% to 50% water changes depending on the level of nitrates

Phosphate:-This is a by-product of fish and decaying organic matter like dead algae or uneaten food. Excessive phosphate levels promote the growth of algae. In new aquariums the test results will usually be nil or less than 0.1 ppm

Carbonate Hardness kH:-The measure of dissolved carbonate and bicarbonate ion concentrations. The Carbonate Hardness is an important measurement. Strong carbonate hardness can mean a very stable pH. Marine aquariums should have a kH reading of 80-120 ppm. The carbonate hardness levels deplete as a result of the breakdown of waste products by bacteria via biological filtration. Carbonate Hardness testing would be the next test to do when pH test results fluctuate.

Maintenance of your water and tank:-Ensure you un-plug all your filters and heaters prior to any cleaning activity. Remove any visible solid waste by siphon hose, be careful and don’t move your gravel around too much this can upset the good bacteria.

Weekly - Do your water quality testing, clean any algae build up on the glass and remove about 5% to 10% of water. Replace this water with fresh seawater (either sourced from the ocean or made from aquarium sea salt).

Monthly - It is advisable to remove your hitching posts and decorations and give a clean in clean sea water to remove any algae build up

Hygiene is a critical issue with aquariums so NEVER use any detergents or add foreign water (from another tank e.g. the water that comes in the bag when you purchase your seahorses) to your tank. It may contain nasties that you don’t need added to your tank.

Adding your Seahorses If you have an established seahorse tank with other inhabitants, it is common practice to quarantine new seahorses for a day prior to adding them to your tank.

When you collect your seahorses from your aquarium dealer, take a temperature reading of the water they are in and then check your tank/quarantine bucket temperature. If there is a major difference float the bag in your quarantine bucket/tank until they adjust.

If these are your first seahorses, they can be added to the tank once you have ensured all your parameters are at the recommended optimum keeping requirements. Never add any foreign water (e.g. the water in the bag your seahorses came in) to your tank.

It may take a day or two for them to settle into their new environment. They may not be very active or feed immediately.

Stocking Densities:-The following are the minimum recommendations for stocking your seahorse tank. When purchasing your seahorses, it is important to find out what size they will grow to. You also need to make allowance for any tank mates you might want.

Even though juvenile seahorses can be stocked at higher densities two or three times higher than the recommended adult rates below, it is important to remember that they will grow and you will not want to be replacing your tank every year.

Small Species: (e.g. H. breviceps) < 10 cm adult height - 1 pair adult per 15 litres (5 US gal)

Medium Species: (e.g. H. kuda, H. whitei) < 16 cm adult height - 1 pair adult per 30 litres (10 US gal)

Large Species: (e.g. H. abdominalis) > 18 cm adult height - 1 pair adult per 50 litres (15 US gal)

Seahorse Food Captive bred seahorses will readily eat frozen food sources like brine shrimp, mysids etc. These are purchased from your aquarium shop in an ice cube form.

To feed out these foods you break off the required amount from the frozen block and add it to the tank (while still frozen). The block will float and as it defrosts the plankton will begin to float around in the tank (it is important to have good water flow). The seahorses will see the food moving in the water column and snick it up.

While frozen foods are adequate for nutrition it is advisable to feed your seahorses some form of live food at least weekly. Live brine shrimp can be purchased from most aquarium shops. Variety in frozen food sources also aids in nutritional levels for your seahorses.

Large seahorses will show no interest in newly hatched brine shrimp, they require the brine shrimp to be >3 mm.

A large adult seahorse can eat up to 20-30 adult brine shrimp a day. Smaller horses will of course eat less. Baby seahorses require smaller foods like newly hatched brine shrimp nauplii, copepods or rotifers.

Feeding is recommended once or twice daily. Do not overfeed as this will deteriorate your water quality. Variety of food sources is highly recommended

Remember seahorses have no teeth, they suck their food through their tubular snout, so all food must be sized accordingly. If it is too big they will not be able to eat it.

When feeding out fresh live food it is important to rinse the food in fresh sea water prior to feeding. Bacteria and other pathogens can come in with brine shrimp. By rinsing through a fine mesh net with clean water, you are minimising the chances of any bacteria being introduced to your tank.

The nutritional value of brine shrimp can deteriorate rapidly if they are not fed. Find out the day your shop gets their live food in and put your order in. Feed out as soon as possible. If you want to keep them for a few days they also must be fed.

The Courtship Dance, Pregnancy and Birth The courtship dance is probably the most spectacular dance you will ever see!

The male and female seem to take on a glow or slight colour change, this attracts the other partner and encourages them to begin the performance.

The male will almost bend in half as he displays to the female that his pouch is empty, the opening at the top of the brood pouch just below the anal fin will open quite wide and the inside of the pouch will be clearly visible.

The male then lowers his head just like a horse prancing and circles around the tank displaying himself. The male and female will link tails and prance in synchronised motion around the tank. This courtship dance may stop and start again for several days until the female is ready to part with her eggs.

When both are ready for the egg transfer they will rise through the water column. The female will position herself above the males open broodpouch.

A clutch or string of orange eggs will be deposited into the males pouch. Some may fall out or be left on the male after he closes his pouch, these will not be fertile. The male will depart to a quiet spot and roll around, this is done to settle the eggs into his pouch, he fertilises them and begins the pregnancy.

His pouch will now look slightly bigger and firmer. If your seahorse has a light coloured pouch you should notice it darken over the next couple of weeks.

If you have noticed your male to be pregnant, it is wise to check your pumps and filters, they may need to be covered with net material ensuring the baby seahorses don’t get sucked into the openings or even better move him to a maternity tank for the duration of his pregnancy.

The birth usually occurs during the first hours of sunrise. The male goes into labour and gives birth to live young. The males pouch will open and he almost shoots the young out. They may come out ones and twos then in small groups. The size of the young also varies dependant upon the species. Size usually varies from 8 mm to 18 mm.

Problems and Treatment for Seahorses Captive bred seahorses are usually much more robust and disease resistant than wild caught seahorses. But even so, if water quality and or nutrition is less than optimum, infections from parasites and bacteria can occur.

Some antibiotics can have adverse affects on seahorses and are recommended as a last resort only. Before you medicate any seahorse ensure you are treating them with an appropriate medication and adhere to the dose rates stated on the packet. Always medicate in a hospital tank – never treat your whole tank (unless absolutely necessary) as you can damage your biofilter or harm other tank inhabitants.

Fresh water baths (for approximately 2–4 minutes) as a treatment for bacterial and parasite problems should always be the first treatment. De-chlorinated fresh water, (to ease the stress ensure the temp and pH of the water is the same as the water they have just come from) an added airline and something to hitch to also help with stress.

Fresh water baths are sometimes used before adding new seahorses to an established tank. The fresh water should immediately kill most seawater parasites.

Topical treatments such as diluted Betadine can be used for any external lesions or sores (skin rot), a dip of the affected area, after a freshwater bath, in a 1:5 Betadine/water solution (Active ingredient Povidone-Iodine w/v 10%). If you are treating an area of the head, do not dip the seahorse, but apply with a cotton bud.

For more serious internal bacterial infections or internal parasites a Formalin (37% Formaldehyde) bath at 200 ppm—(1 ml per 5 litres of sea water) will assist. Horses can be bathed in this treatment for up to 1 hour, but be sure to add aeration and hitching posts. If your Formalin contains white sediment in the bottle, do not use.

Be aware that Formalin is harmful, ensure you use with care (use gloves and do not pour down sink or septic systems when finished). A clean plastic bucket will be an adequate hospital tank for the bath.

It is a good idea to isolate any seahorse in a hospital tank if you think there is a problem, this lessens the risk for your other tank inhabitants. It is recommended to only ever add medications to a hospital tank that contains no filtration.