Sea Horses

[JSTR]

Wow, talk about not enough information and alot of wrong information.

I would strongly suggest you have a look at some educated information.
Try - http://www.seahorse.org/
and - http://www.syngnathid.org/
Both are site specific to seahorses and their requirements.

Not going to comment on what was post here as I dont know what species of seahorses are being kept or even looked at for purchase.
Will advise that you do a bit or research and reading prior to the purchase as they are not as simple as it is being made out to be.

Having kept and breed seahorses, I will not say that they are really difficult to keep, but they are that easy either. To maximize your success rate with them, try and find out what type of seahorse they are, then research the requirements of that species.

Would offer more but would need to know alot more information than you have supplied. Tank size, species and others.

HTH
Good Luck