Dwaef Seahorses got me started in saltwater in 1962. When my grandmother gave me a "Dwarf Seahorse Kit" for Christmas from the back of an "Outdoor Life" magazine. As a "kid" I kept Seahorses in plastic shoe boxes that held about 2.5 gals and have continued keeping seahorses since! Dwarf Seahorses feed best on newly hatchet live brine shrimp and small "pods". I've not ever been successful getting Dwarf Seahorses eating anything but live foods. One "trick" I used in my Seahorse tank is keeping lots of Peppermint Shrimp with them! Most people don't realize that Peppermint Shrimp will produce lots of young (they don't notice them because of high currents and strong filtration). But the Seahorses, Pipefish and many other fish and inverts love to eat the baby shrimp! Other species like Hippocampus erectus, H. comes, H. kelloggi , H. kuda and H. reidi I've been able to get them eating frozen foods. Some will take it readily and some take a little patients. It's not the species, but each Seahorse has it's own personality. Some are just down right lazy and other are aggressive feeders! As far as tank mates............ most of the SMALL Goby's, Blenny's (Sailfin Blenny's, Emblemaria pandionisone is one of MY favorite), Pipefish, Octocorals and snails do great with them. I've also kept Geometric Hawkfish with them too. The NOT'S to put with them ........anything aggressive! Also most crabs, anemone's, corals and urchins.