The Short Verdict for This Mix
Dwarf rainbowfish can live safely alongside adult shrimp and snails, and this is a combination many planted-tank keepers run for years. The rainbowfish are active, surface-leaning schoolers with small mouths and a generally easygoing temperament toward tankmates they cannot swallow. An adult cherry shrimp is too large and too quick for most of them to bother with, and a snail behind its shell and operculum is essentially ignored. The exception is size, not temperament: a shrimplet in its first days is small, soft, and drifting, and to a dwarf rainbowfish it registers as a snack rather than a neighbour.
Why Shrimplets Disappear Even in a Peaceful Tank
Nothing aggressive has to happen for a shrimp colony to stall in this setup. Female shrimp release babies that spend their early life grazing on surfaces and making short, exposed hops between them. Dwarf rainbowfish patrol the middle and upper water, exactly the space a hopping shrimplet crosses, and they are built to snap up small invertebrates from the water column in the wild. A colony can therefore hold its adults perfectly well while quietly losing most of each new generation. Owners often misread this as poor shrimp health when the real cause is steady, opportunistic predation during the babies' most vulnerable week or two.
Cover That Actually Protects the Young Shrimp
Generic planting is not enough; the cover has to match how shrimplets hide. A thick clump of moss, a dense mat of fine-leaved stems, or a pile of small stones with tight gaps gives babies refuge spaces the rainbowfish cannot enter. Place that refuge near where the adult shrimp already graze, so newborns reach it in one short hop instead of crossing open sand. Let the shrimp establish and start breeding before the fish go in, because a colony that begins with several overlapping generations can absorb some losses and still grow. Feeding the fish well at the surface also helps a little, since a satiated school investigates the planting less, though it never removes the instinct entirely.
Snails in This Combination
Snails are the untroubled part of the question. Dwarf rainbowfish do not crush shells, do not harass antennae persistently, and do not compete with snails for food in any meaningful way, since the fish feed in the water column and the snails work the glass, wood, and substrate. Mystery snails, nerite snails, and the small hitchhiker snails that arrive on plants all fare fine here. If snail numbers fall, look first at food availability and water conditions rather than at the rainbowfish. The only indirect issue is overfeeding: extra fish food fuels snail population booms among the small species, which is a feeding problem, not a compatibility one.
Setting the Order of Arrival
Sequence matters more than most stocking lists admit. Shrimp added to an established rainbowfish tank get investigated by every curious fish at once, while shrimp given a few weeks alone learn the refuges and begin grazing confidently. Add snails at any point. Introduce the rainbowfish as a proper group rather than one or two at a time, because settled schoolers are calmer and less fixated on newcomers than a lone, unsettled fish. After stocking, judge success by the shrimp colony over months: stable adults with slowly rising numbers means the balance works, while adults only, month after month, means predation is winning and the fish belong in a shrimp-free tank. Keeping that arrival order, the refuge layout, and the full stocking list together through KinsLe Family Sharing means everyone in the household works from the same plan instead of improvising additions at the shop.