Seahorses are a wonderful and time consuming hobby. I agree with the tall tank. I converted my 90 gallon into a refugium off of my main tank and have reidi's. I had an Erectus in there that I bought from Jenn. I just lost him after his second set of fry were born.
You will definately want
captive bred (CB) not wild cought (WC) for the simple fact of feeding. The wild one will require live food and are hard to train to eat frozen. You will need alot of frozen brine and mysis to feed the CB ponies. If your gonna go with a 20 g, I would make it a 20 high not 20 long. they like to use the entire height of the system. Aslo they will require many items to hitch on. I would suggest some culerpa and a good bit of live rock also. No matter how they were raised, they have an inherent need to hunt their food also. A large population of critters in the system is advisable.
Unless you want to deal with a lot of work and heartache,I would get all one sex vs males and females.This way you won't have to deal with rearing fry and hatching out food daily to feed them.
You can purchase CB online or from a lfs. Make sure if you go to a lfs, that you see them eat frozen food first. The CB will usually be smaller than the WC becouse the are sold when they are younger. Around here you can expect to pay $60.00-$70.00 each.
I strongly urge you to do alot of reaserch before you take this on. They can be alot of work but are worth it in the long run. JMHO
