so ok first of all guys im new to salt i have a 55 gallon fresh water but my girl wants to keep seahorses and iv always wanted salt so im taking hte plunge my question is if i have enough live rock would i need a cycle?
Absolutly. Your live rock helps the cycle & stability of your water quality, however when you transition from fresh to saltwater many will remind you patience is the #1 rule. Especially if your talking seahorses already. Many advanced reefers on this site have given me countless helpful advice. Give the members here lots of detailed info such as tank size, filtration, lighting, plans, goals etc. and they may better steer you in the right direction. Welcome to the site!
What size tank are you trying to keep? generally a pound of rock per gallon or more is recommended, i go with about 1.5 pds per gallon but that is preference. For seahorses you will require a special setup and you should not attempt it unless you are serious about the care and environment they will.
A ten gallon is not big enough for anything but the dwarf seahorses which are RIDICULOUSLY hard to care for. If she's serious about wanting them, you're going to need a bigger tank.
I would suggest researching in the seahorses and pipefish section, there is a great article posted there about starting a seahorse setup. I'm not familiar with their specifics though im pretty sure they require taller tank and have special water flow needs etc. I would try to find lil_fish as she knows quite a bit a bout seahorses from experience.
Sorry, i was really tired when i wrote that last night.
I dont mean to discourage you from getting seahorses, i just want to make sure that you understand the commitment and special care they require. For many people, its more than they are able to do.
Please read that article and and the other ones linked in that article so you can make an educated choice about whether or not to get them.