How Many Shrimps Per Gallon?

Freshwater shrimp keeping or breeding may not be an intuitive skill, but that shouldn’t discourage beginners from joining the hobby. One of the first problems to avoid is overpopulating your aquarium. You can prevent this by determining how many shrimps you should have per gallon of water in your tank.

The viable number of shrimps per gallon of water varies by species. Up to 10 freshwater dwarf shrimp (1-1.5 inches) survive on a gallon. Up to 5 larger shrimp (1.5-2 inches) survive on a gallon. The viable number of shrimps per gallon increases with water quality, based on species-specific needs.

All types of shrimp vary in the care needed to survive, grow, and stay healthy. Different types of shrimp grow to different sizes and require different conditions to thrive. Different tank environments also support different shrimp types. That means that the number of shrimps in your aquarium should be determined by more than a written standard.

How Many Shrimps Can You Keep In A Gallon Of Water

It’s important not to over-stock an aquarium. Breeders often overestimate the number of shrimps that can survive in a set volume of water because they seem so tiny compared to their tank. But even tiny shrimps can outgrow the availability of resources in their environment.

Neocaridina is considered the go-to genus for inexperienced people taking up shrimp breeding. These are the small or dwarf freshwater shrimp types of around 1-1.25 inches, like the cherry shrimp, babaulti shrimp, or snowball shrimp. Their small size allows you to keep more shrimps per gallon than you would with many other bigger genera.

The maximum safe number of dwarf shrimp to keep per gallon of water is 10. However, starting with five shrimps per gallon is recommended until you are sure the environment is healthy and can support more. That way, you can gradually get the hang of caring for shrimps and, most importantly, spot any issues that may arise in the tank more quickly!

Another common freshwater shrimp genus is Caridina. Though they have a very similar appearance to Naeocaridina, with bright colors and a variety of patterns, they tend to grow a bit bigger and need more space and resources. Caridina shrimp types grow to around 1.5-2 inches and thrive with no more than five shrimps per gallon.

Which Aquarium Conditions Support More Shrimps Per Gallon

The importance of water in a shrimp tank is not limited to volume. Water contains many of the minerals and salts needed for the shrimps to survive, grow, and even breathe. The more suitable the water, the more shrimps can survive on each gallon.

Each type of shrimp has a set range of water parameters required to thrive. These factors bring us back to knowing your shrimps. As a breeder or keeper, you need to adjust the water conditions to the type of shrimp; or pick a shrimp that is suited to the conditions you can provide with the equipment you have.

When the water’s living conditions and resource availability are optimal for the species, your aquarium will sustain more shrimps per gallon. There are three key parameters dictating the suitability of freshwater to sustain shrimps: the acidity or alkalinity of the water (pH), the total dissolved solids (TDS), and the general hardness (GH) of the water.

GH is a measure of the concentration of magnesium and calcium salts in the water. Adding these salts will raise the GH while boiling, or adding a deionizer will lower the GH. GH testing kits for freshwater aquariums are freely available. Maintaining the optimal GH for your type of shrimp is critical, as magnesium and calcium are key elements for their growth and many biological processes.

All shrimps are pH sensitive. Measuring pH is a relatively simple checkpoint because it requires very little expertise. If you know the type of shrimp, you can maintain the water pH in the optimal range specified for that species.

TDS is determined by the different types of salts and minerals in the water. These minerals include water conditioners, fertilizers, or waste from shrimps (ammonia). TDS is typically the deciding factor in how frequently the aquarium water needs to be changed. A TDS meter will help determine when the water needs changing and helps avoid buildup in the tank.

A buildup of mineral and salt solids in the tank could introduce a level of toxicity in the aquarium and stress the shrimp. Continual stress can negatively impact the growth and health of your shrimps, meaning fewer surviving shrimps per gallon of water. Adding a filter to the tank could help maintain healthy mineral levels in the tank.

There are shrimp species that are hardier and adapt better to a wider range of aquarium conditions. A good example would be the Neocaridina davidi or cherry shrimp. These shrimp species are relatively easy to care for and a good pick for someone who is still learning the ropes of keeping the maximum number of shrimps healthy in each gallon of water in their tank.

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How Breeding Rate Affects Shrimp Viability In An Aquarium

The number of shrimps you initially add to the tank will change over time as the shrimps breed. This fact may seem obvious, but many shrimp keepers forget to adjust the conditions of the aquarium to the increased number of shrimps growing and living inside.

As the number of shrimps in the aquarium increases, food, and organic waste also rise. With more of these waste compounds released into the water, the delicate shrimps are exposed to increasing levels of salts like ammonia and nitrates. This high salt exposure could harm their respiratory systems or the proper development of their exoskeletons.

Each shrimp can carry up to 30 eggs at a time. After the 2-3 week hatching period, this presents a significant expansion of your shrimp population. So, you must account for this difference by moving some shrimps over to a new tank and balancing out the water-to-shrimp ratio – before the new shrimplets are harmed or their growth gets stunted.

Ideally, you should always adjust the aquarium conditions before you can see problems such as buildup arise. When it comes to the sometimes-tricky business of maximizing your shrimp-to-volume ratio, prevention is better than treatment.


Understanding the right aquarium conditions for shrimp keeping or breeding can be tricky. But if you start small until you get comfortable taking care of the shrimps, you can quickly get a feel for adjusting their environment according to their needs. Once you’ve got the practice, you could be breeding large numbers of shrimp per gallon in no time!