These are VERY delicate little guys, i had some and just traded them away not long ago because i couldn't enjoy them like i was hoping with everything else going on in my life./...but the tank recommendation is 5-10 gallons, no bigger because they are SMALL, an adult will fit on a quarter...babies will fit on a dime....any and all flow creators in the tank must have some sort of thick sponge over the intake so they dont get sucked in...it doesnt take much....you also have to feed live brine shrimp twice per day so water quality is a very big issue since your feedings are so big compared to the tank size...if you look at some of my threads you'll find some about my dwarves i had and the feeding schedule, my hatchery setup and tank....also if you are planning on doing the "live" setup panacur is needed....they kill hydroids, which are deadly to these guys as they can sting them like crazy...so you have to dip everything in panacur to make sure you dont bring anything dangerous in the tank(even dip snails,etc)....if you are new to saltwater these are definitely not recommended, if you have a lot of experience there you can probably do it, but they are not recommended for the first time having seahorses....it takes a LOT of dedication to feeding, water changes, and cleaning the tank.