Feeding is probably the most difficult part about dwarf seahorses. Here is some basic info from allthesea.com
Seahorses - Aquarium Settings
Seahorses require many holdfasts, as they become stressed if they cannot hold onto something with their tails. The best holdfasts are natural surfaces such as "living rocks." Excellent substitutes are soft plastic plants. They should be quite tall and have many branching parts. It is also important to provide a reasonably complex environment so the seahorses can escape into hidden corners. They become stressed it they are too exposed. It's also a good idea to have a tank backing to give them a reference point and to help them orientate.
Seahorses - Companions in the watertank
It's very important not to put seahorses in an aquarium with fast, agile fishes or with aggressive feeders. They tend to do best in invertebrate aquaria but otherwise they can be kept with dragonettes (Callionymus bairdi), tiny trunk fishes (Lactophrys trigonus), small pipefishes (although it has been suggested that these may become 'fin pickers'; as they grow), blennies, etc. Never place seahorses with active feeders such as damselfish, puffers, butterfly
Sea Fish or angelfish. Blennies in particular make quite good companions because they help to keep the tank clean.
Seahorses - Lighting in your watertank
Seahorses interact most in the hours just after dawn. I suggest, therefore, that you keep seahorses on 3 hours half-light/10 hours light/3 hours half-light/8 hours dark. The half-light can be produced by a lamp some distance from the aquarium.
Seahorses - Feeding your sea-horses
Seahorses eat a great deal but are rather particular. Feeding seahorses is one of the most difficult aspects of keeping them in captivity. Seahorses usually eat only live, fresh food. They need food variety and cannot be fed solely on Artemia as these alone provide a highly unbalanced diet. With patience and effort, you may convince seahorses to eat some frozen foods and these can be a good backup when fresh food fails. However, you must not rely solely on frozen foods as these alone will eventually result in malnutrition and illness.
Seahorses - Healthcare
Seahorse are vulnerable to many fungal, bacterial and parasitic ailments and infestations and few seahorses ever recover from a serious illness. Seahorses should be inspected every day for changes in their health and any ailment treated immediately; one seahorse's illness usually hits all seahorses in the tank very quickly. Any ill seahorse should be isolated at once. If in doubt, I risk treating them with a wide-spectrum antibiotic.
Buoyancy problems are fairly specific to seahorses. Any seahorse staying constantly near the surface is almost certainly an ill seahorse. You should react at once as buoyancy problems are serious and often fatal. Again, prevention is better than cure. Try to ensure that you have no dissolved gases in your system (in contrast to suspended gases) as these appear to be a major trouble source. Symptoms are the following:
- A grossly distended body - by then, the problem is far advanced (3)
- Inflated pouch not due to pregnancy - avoid wishful thinking if the animal hasn't been near a female (1)
- A constant head down position when swimming (1,2,3)
- The tail curled well back and up behind the trunk (2)
- Small bumps on body surface (2)
- Tightly curled position (when trying to descend), held for an unusually long period with little progress (1,2,3)
- Immediately bobbing to surface after release from holdfast (1,3)
- Lying approximately horizontally at water surface, even if the tail is holding something (1,3)
The number(s) in brackets refers to possible causes and solutions below.
- Air trapped in the pouch (males). You can try the following to release the air. Do not lift the animal out of the water. Keep the seahorse underwater and massage the pouch gently. Hold the head upwards so the air can escape. Stretch the pouch between your thumb and forefinger. Manipulate gently and insert a hollow, blunt small-bore object (e.g. plastic tubing). Exert gentle pressure on the pouch. The gas may escape via the tube. Move the tube gently around if needed. You may need to suck on tube as you massage pouch (yuck!). Ensure that you get the air out. Then monitor that animal as buoyancy problems tend to reoccur in the same animals. This problem is especially prevalent around courtship periods and occurs if males dilate the pouch opening in air streams.
- Air trapped under the skin is a more acute problem. Use a sterile syringe needle (with a tiny diameter). Slip it gently (at an angle) under the skin to pierce a small hole. Remove the needle and then massage the bubbles out while the animal is under water. Pierce all the bubbles you see because they are usually interconnected and missing once causes a repeat performance. Keep the Sea Animal in a very clean tank after puncturing the skin.
- Air trapped internally is very serious and generally results in death. I am unable to suggest anything useful to do in this case. Try to detect this condition early on as it only worsens. Seahorses appear to have no solutions of their own and become very stressed by such buoyancy problems. Seahorses in this condition have massively bloated bodies and get several related problems such as sores, skin cracks, frayed and tattered tails, bony plate separation and internal injuries.