I just posted this on another persons thread, but this would be for you to
Dwarfs are def not a beginners horse. Erectus are about the easiest, but require a 35 to 40 gal tall tank. Horses must have perfact water conditions as well as lower temps. 72 to 77 degrees with low to med flow through out the tank. They are pron to bacterial infections, and must be feed two to three times a day. You cannot have any thing in the tank that will sting. tank should be cycled and running no less them 4 to 5 mo before adding any horse. You really need to research thier care, including how to treat them in case of illness. If you are going to pay 50 to 100 dollars for a horse, you really need to know how to take care of them.
Only buy CB (captive breed) eating frozen. They eat frozen mysis. BBS are not healthy for larger horses. They need place to hitch and also places to swim and hunt. Pods are good, so are macros. Hydroids, and stinging corals are not.
Not trying to be harsh, but you really need to start with one tank, and leave the horse for 6 mo or more down the road. Reasearch first.
TeresaQ