Neocaridina cherry shrimp do not need a heater in a normally heated room, because they are comfortable anywhere from about 18 to 26 degrees Celsius. If your room sits reliably in the high teens or low twenties, an unheated shrimp tank is fine, and I run several of mine that way. A heater becomes worth adding only when the room gets genuinely cold or swings sharply between day and night.
Why cherry shrimp cope without one
Cherry shrimp are hardy dwarf shrimp with a wide comfort range, unlike tropical fish that want a steady 24 to 27 degrees. Within their range they simply live faster when warm and slower when cool. Around 22 to 24 degrees they breed briskly; drop to the high teens over winter and the colony carries on, just more slowly. That tolerance is what lets you skip the heater in a heated home.
What shrimp dislike far more than a cool tank is a sudden change. A tank that drifts between 24 degrees by day and 15 by night, next to a draughty window or an unheated conservatory, stresses them more than a stable 18 would. In that situation a small heater set low, purely to stop the night-time crash, does more good than one set high.
When a heater is the right call
Add one if the room drops below roughly 16 degrees in winter, if the temperature swings several degrees between day and night, or if you keep Caridina crystal and bee shrimp, which are fussier and appreciate a steadier, cooler range held in place. A cheap adjustable heater of 25 to 50 watts is plenty for a shrimp tank.
What temperature actually does to the colony
Heat is a throttle on the whole colony, not just a comfort setting. Warm them to 24 to 26 and they breed fast, moult often and grow quickly, but they also live shorter lives and use oxygen faster, so warm shrimp tanks want decent planting and a little surface movement. Cool them into the high teens and everything slows: breeding pauses, moults space out, and the colony ticks over on less food. Neither is wrong. It is why a heater is really a decision about what you want from the tank rather than something keeping the shrimp alive. If you want a booming, fast-breeding colony, hold it warm and stable. If you are happy for it to grow slowly and just want healthy animals, an unheated tank in a heated room does that on its own.
A quick FAQ
What temperature is best for cherry shrimp? Around 22 to 24 degrees for fast breeding, though anywhere from 18 to 26 keeps them healthy.
Can shrimp live in cold water? Neocaridina survive brief dips into the low teens, but sustained cold slows them right down and stops breeding. It is tolerance, not a preference.
Do shrimp and fish need the same heat? No. Most tropical fish need a heater; cherry shrimp usually do not. In a shared tank, set the heater for the fish and the shrimp will be fine.
For the full picture on building a colony, water chemistry and tankmates, see the cherry shrimp care guide.