The first precaution to take is without delay to transfer the babies to a nursery or a small tank . Due to their size and their lack of strength they may be trapped by the pumps, the filters the algae etc. If you cannot isolate the newborns, secure the entries and exits of the grids by nets or plastic bars with very small holes in order not to interfere with water circulation. In any case it is better to put them in a nursery which is a calm place where they can move and eat easily. Thus you will avoid accidents (swallowing of tiny algae, filaments, choking by an adult or being taken in a too strong stream).
Hence you need to buy or create an appropriate nursery or a small tank. The babies need little space during the first two months. (Ten of them can live in a standard nursery until they get to that age). You had better choose a model with small holes on the sides and not with slits, in order to avoid stuck tails or bodies and food loss. It is also recommended to put a "caulerpa-stem" which is light soft and natural, so that they may hang to it when they rest or sleep. Do not add gravel to the bottom of the nursery so that not to make food searching too hard for these small apprentices.
Gently and regularly shift the nursery from one side to the other in order to renew water and help the evacuation of toxic elements. Depending on the size of the tank, the nursery needs to be cleaned regularly to remove undesired substances and dirt. The keeping rules concerning tanks are relevant. Do not use a siphon to clean the nursery as the babies might be sucked up. The best thing to do when it comes to cleaning, is to transfer them into another one. It is also possible to remove the waste without transferring the babies by using a small plastic sieve. In that case be careful not to wound or capture them. Doing so requires time, patience and slow movements.
A sieve being a rigid, practical non stressing tool is recommended when transferring seahorses of all ages and sizes, especially when they are around 10 mm long. Actually both adults and babies do not enjoy being stuck in nets. Freeing babies in a net without harming them is almost impossible. If you have no sieve, remove them delicately in your hands, but sterilize and wash them carefully first. Actually, this should be done every time you interfere in a tank. Using you hands requires caution. If other solutions exist use them in priority, because not only the protecting mucus can be damaged but a wrong handling may cause severe harm. An adequate cleaned material is the best and less dangerous solution.
Breeding, above all, requires a good imagination, a do-it yourself skill, and know how.
For tropical species, see to keep a constant temperature of 26 Celsius (around 78.8 Fahrenheit) at least, and very clean water. The smaller seahorses are chilly and vulnerable. In Summertime, temperatures up to to 29 degrees Celsius (around 84,4 Fahrenheit) are accepted without any problems. Any little change of water parameters having no effect on an adult may quickly lead your young guests to certain death. On the next day you may find them wound up at the bottom. An incessant precision is then compulsory.
For subtropical species, keep a temperature of 23 degrees Celsius (around 73,4 Fahrenheit), do not exceed 25 degrees Celsius (around 77,0 Fahrenheit).
For temperate water species, keep a temperature of 20 degrees Celsius (around 68,0 Fahrenheit), do not exceed 22 degrees Celsius (around 71,6 Fahrenheit).
Keep the babies in the nursery up to the age of two months, or more if necessary when you know that the food intended for adults is correctly absorbed and that pumps and filters are not a danger anymore (this subject will be developed later on). If you have enough room it is preferable to keep the babies in a restricted area until they are 3 months old, when they may be considered mature. Actually, if an adult can bear being disoriented for a few days this should be avoided when it comes to babies. They would feel lost, stop and/or find it difficult to eat, because food is scattered, due to lack of habit, or because gravel covers the bottom. Young animals have not got enough reserves to survive more then a few days. You may account for some losses during this period but should not worry. As it is the rule of nature only the fittest survive, however a 95 % rate of success is possible if you follow the necessary requirements.
When you definitely put the seahorses into the tank, keep secured for safety reasons the openings (pumps and filters) as said before. Do this until the age of 4 - 5 months, according to the size of the animals. Some of them may remain smaller for a long time without being dwarfs. Several of my guests were 1.5 cms long whereas the brothers and sisters reached 3 cms, nonetheless they became magnificent adults which mated perfectly.
Contrary to certain writings, never sacrifice any young each has to have its luck!!!
When they are born, babies have only a small food reserve considered in approximately 4 to 6 hours, but are quite capable of eating, hence it is necessary to look after them immediately. Unfortunately, scare food exists for such small animals. They mainly feed upon
micro-plankton. There exists a specific foodstuff with micro-plankton, but it pollutes the tanks. Another solution is to keep hatcheries.
To a seahorses lover, the simplest way to feeding its newborns is to raise new hatched artemia, however you may encounter difficulties due to the quality of the bought eggs (cysts). Be careful to buy or construct only hatcheries (salt density 1017 - surrounding temperature) which are able to isolate perfectly the eggshells from the hatched artemia. Never introduce eggshells into the tank, the babies seahorses may eat them, and quickly die. You must also provide for giving frozen or live new hatched cyclops (or other copepods) as a subsidiary and/or complementary food. This helps them first getting used to lifeless food, second makes it easy to assure the transition to another kind of food. You can also try the micro-plankton such as rotifers. At this age the mouth is small but the appetite is big. Feed them at regular intervals of 3 to 4 hours, 4 times a day and see that they get good rations.
Having eaten their fill during the day, the babies seahorses can spend the night without any extra needs, but should be fed early on the next day. In order to obtain good results regularly add vitamins and trace-elements to the water (same rules as for adults).
If you cannot dispose of new hatched artemia at the babies' birth, or if they are reluctant to eat them, it is possible to provide them with dry fish food, but do not exceed 3 days. They accept a mixture combining on one hand milk by-products: fish, mollusks, cereals, yeast and algae; on the other hand a compound of dried micro-organisms. Both mixtures must be ground to powder before being given.
Starting from 1.5 - 2 months of age, progressively insert frozen adults artemia. Sort them out and only take the smaller ones, or slice them so that they still look like animals. If you do not do that, they may choke to death or refuse to eat. For the same reasons avoid living artemia which move too fast and have several sizes. Avoid frozen mysis because of the shapes of their heads and tails. Stick then to artemia while providing the same feeding as seen before until each animal eats. If they refuse adults artemia, go on feeding them with frozen cyclops and the hatched artemia until they accept adults artemia. If one or several individuals are still reluctant, try at this moment only some frozen mysis, but get only very small frozen specimens and squeeze them with your fingers in order to flatten them. Be careful to avoid choking risk.
Then you may progressively stop the specific feeding of newborns. When they are 6 - 7 months old, you may give all kinds of mysis and artemia, living or not.
In spite of all your efforts your small guests may still choke. The first symptoms are a jerky swimming, dizziness, excitement, difficult breathing, sudden beak strikes, diving to the bottom. The first thing to do is to watch them after each food distribution. In presence of one the choking symptoms, provided they still breathe, take them gently and delicately between two fingers (head downwards) and shake them head down until the piece of food is expelled. As soon as you see the piece of food remove it from the muzzle.
Whatever their age, some seahorses refuse eating and die in spite of your efforts. This is part of the drawbacks of seahorses breeding.