The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
Check out seahorse.org, they have pretty much all the info you need. I don't have any but maybe some day when I feel capable. They are pretty demanding.
I did some research on them a while back and it seems like conditions vary by species. Seems like thy are low on the genetic totem pole lol... Low flow, very clean water.
What I found surprising is against popular belief they can be housed with other fish if done in a smart manner
Low flow is actually a pretty common misconception. Seahorses do best with a moderate to high flow. I personally wouldn't go over a 20x turnover rate, but I know people have done more. My goal is 10-20x the overall tank volume. This also helps with keeping crap from building up in "dead spaces". Just be sure to cover all in takes and overflows, and have some sheltered areas that are out of the direct line of powerheads and returns.
Most species require a minimum of a 29 gallon aquarium for a pair, and add 15 gallons for each additional pair.
Price is $40-$150 for true captive bred seahorses, with $60-70 being average. One concern are "tank raised" seahorses - seahorses that are imported from overseas and grown in natural seawater. They tend to be cheap (some times as low as $26 on Live Aquaria), and far too small. They have a very poor survival rate in captivity.