If you would like to keep Red Cherry Shrimps (or other Neocaridina Shrimps) in a fish tank that can hold 2.5 gallons of water, then you can take a look at this guide at Aquarium Blueprints to see what the appropriate number you can start off with.
Bio Load
Before we come up with a number, there are several important factors that you need to consider. The first of which is the bio load of a Red Cherry Shrimp.
When compared to fish and other species in the aquarium hobby, the Neocaridina Shrimp do not produce much organic waste at all. Therefore, you can easily disregard the “1 inch per gallon” rule if you are only keeping shrimps in your tank.
Biological Filtration
On the other hand, you should also take your biological filtration into consideration. For the uninformed, you need beneficial bacteria in your aquarium in order to keep your tank water balanced.
When it comes to the Neocaridina, you should aim to have 0 ppm of ammonia, 0 ppm of nitrites and less than 20 pp, of nitrates.
Cherry Shrimps are extremely sensitive to any spikes to ammonia and nitrites; therefore, adding too much to a tank at once can cause water quality issues. The opposite can also be true, however, as having too little shrimps can result in a large die off of beneficial bacteria, eventually causing spikes in ammonia, nitrites and nitrates.
Reproduction
If you have male and female Red Cherry Shrimps, then odds are likely that they will eventually reproduce. While the babies start off small, they will mature to adult size at around 2 to 3 months after birth.
The good news is that the population of your Red Cherry Shrimps will self-regulate as female should produce less eggs if the tank becomes too crowded and/or there is less food to consume. Therefore, it is not likely that your aquarium will be overrun with shrimps to the point where there is a massive die-off.
Summary
When it comes to picking the right amount of Cherry Shrimps to keep in a 2.5-gallong fish tank, you must consider the bio load, biological filtration and reproduction.
The Neocaridina species produce very little wastes. Therefore, you need to add enough to your aquarium in order to keep your beneficial bacteria colonies, which are responsible for the biological filtration, alive.
While Cherry Shrimps will reproduce, you won’t likely experience a population explosion as the females should produce less eggs if they sense that the fish tank is getting too crowded and/or there aren’t as many food sources available as before.
For a 2.5-gallon tank, we recommend starting off with around 10 Red Cherry Shrimps. With that number, your biological filtration should easily handle the bio load.
Furthermore, having 10 shrimps makes it likely that there is a good mix of males and females, meaning that the shrimp population should naturally fill out in your aquarium over time.
It is also important to note that Red Cherry Shrimps live around 1 to 2 years at most. If you are getting them at around 1 inch in size, then they are least already 2 to 3 months old.
Not to mention that you may get some die-off in the beginning when you add them to your tank as the Neocaridina species are really sensitive to water changes. So, by having at least 10 shrimps, you have a little buffer to account for potential deaths.
