So im gonna have a spare 10 gallon when i get a bigger tank for my baby Red Ear Slider Turtle that i found in my pool last year. I want something different. I either want upside down jellyfish or dwarf seahorses. I am aware of the fact that each species can only be held in a tank by themselves. I plan on putting in an under-gravel filter, an inch of gravel, and another inch of sand on top of that with some species of grass like plant. I am also aware that seahorses need brine shrimp and the jellies need good lighting. Which one you think i should get?