dwarves 'need' nano?

[Chefbill]

So twice now I've seen write-ups or guides that state "dwarf seahorses need a nano". Why? I get putting an animal in too small a space is bad, but too large? Wouldn't bigger support more biodiversity, pods in particular, as well as helpiung to maintain water quality?

Am I missing something?

 

[vlangel]

I don't keep dwarves but I know the reason they need a nano tank, (around 5 and half gallons) is because they are ambush pedators. They basically stayed hitched while foods just floats past their noses. Then they snick it as its going by, and they need a lot of food. That means that the tank needs a high density of live food to sustain DS and they eat 3Xs a day. That means hatching out a large amount of bbs, not to mention the water changes necessary to maintain a healthy tank. It is not feasible to hatch enough food and do such large WCs in a big tank for most folks.