I keep my tank at 22-23C /71-72F. This allows leeway for the natural heat through the different seasons. In a week and a half of having my new little guys in I have about 5 berried girls and about another 4 waiting to berry. I have read and heard that keeping the heat in the tank at a higher rate can reduce the lifespan so tbh I wouldn’t recommend it. But in saying this you can have your temp up to ridiculous F but if your conditions ain’t right in that tank you will have very little success as well. A shrimp tank is very delicate (trust me I know after I poisoned my tank) so everything needs to be on point or you will have a lot of issues