How Many Ghost Shrimp Should Be Kept Together? (1-75 Gallons)

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The first question I had when I started my ghost shrimp colony was how many of them should be kept together. As time passed, I realized that not only is it essential to match the number of shrimp to my aquarium, but their genders as well. I also learned that the answer relies on the aquarium’s condition and what it already contains.

An average aquarium can hold five ghost shrimp for every gallon of water. For example, 5-gallon tanks can accommodate twenty-five ghost shrimp, and 10-gallon tanks can hold fifty. However, tanks with plenty of vegetation or fish should be filled with fewer shrimp to avoid overcrowding.

As we move forward, I will show you how many ghost shrimp your tank can hold, depending on its size. I’ll make a distinction between tanks ranging from 1 to 75 gallons. Then, I’ll show you how many ghost shrimp are required to start a colony and how to deal with a ghost shrimp outbreak.

How Many Ghost Shrimp Should Be Kept Together?

Most aquarists know that ghost shrimp require 5-10 gallons of water, at least.^[1] But that doesn’t tell you the number of shrimp you can keep in a 5 to 10-gallon tank or bigger.

The exact number will vary depending on the aquarium size. The common practice is to keep up to five ghost shrimp for every gallon of water.^[2] Though, that number occasionally fluctuates, rising as high as ten shrimp and falling as low as three shrimp for every gallon of water.

The size of the shrimp, along with factors like the number of tankmates, will influence the final figure. If you want to maintain the standard (5 ghost shrimp per gallon), this is the appropriate number of ghost shrimp to keep for each tank size:

Small-Sized Fish Tanks:

1-Gallon tanks can hold five ghost shrimp
2-Gallon tanks can hold ten ghost shrimp

2.5-Gallon tanks can hold twelve ghost shrimp
3-Gallon tanks can hold fifteen ghost shrimp
3.5-Gallon tanks can hold seventeen ghost shrimp

5-Gallon tanks can hold twenty-five ghost shrimp
6-Gallon tanks can hold thirty ghost shrimp
6.5-Gallon tanks can hold thirty-two ghost shrimp

7-Gallon tanks can hold thirty-five ghost shrimp

Medium-Sized Fish Tanks:

10-Gallon tanks can hold 50 ghost shrimp

15-Gallon tanks can hold 75 ghost shrimp
20-Gallon tanks can hold 100 ghost shrimp
29-Gallon tanks can hold 145 ghost shrimp

30-Gallon tanks can hold 150 ghost shrimp
36-Gallon tanks can hold 180 ghost shrimp
37-Gallon tanks can hold 185 ghost shrimp

Large-Sized Fish Tanks:

38-Gallon tanks can hold 190 ghost shrimp
40-Gallon tanks can hold 200 ghost shrimp

55-Gallon tanks can hold 275 ghost shrimp
60-Gallon tanks can hold 300 ghost shrimp
75-Gallon tanks can hold 375 ghost shrimp

Because ghost shrimp are just 2 inches long, you can keep many of them in a single aquarium. However, you can’t apply the estimations above to every single tank. At the end of the day, the number of ghost shrimp you can keep will depend on various factors, besides the size of the ghost shrimp, including:

1. The Amount Of Vegetation In Your Aquarium

The plants in a tank occupy space. Therefore, you have to account for the number of plants. The more plants you have, the fewer ghost shrimp you can keep. For a heavily panted tank of average size, you should add a maximum of 25 ghost shrimp.

If you care about the tank’s appearance, you should stick to 20 shrimp or less.^[3] A crowded tank isn’t simply a source of discomfort for the shrimp. It is not as aesthetically pleasing.

Don’t expect the ghost shrimp to reduce the number of plants in the aquarium. They prefer to eat dead or decaying foliage. An environment with an excessive number of plants will create crowded conditions for the shrimp.

2. Other Creatures Living In Your Tank

Are you maintaining a shrimp-only tank? If so, the most crucial consideration is the number of shrimp. If you have a community tank inhabited by fish, snails, anemones, and other aquatic creatures, you have to take the size and number of those aquatic creatures into account.

For instance, you can keep 50 ghost shrimp in a 10-gallon tank. However, you can’t keep five angelfish in a 10-gallon tank with 50 ghost shrimp. The tank should be large enough to accommodate the ghost shrimp and their neighbors.

If your shrimp are overcrowded because of the other creatures in the tank, you can get a bigger aquarium or keep fewer shrimp. As a rule of thumb, for each fish, your aquarium occupies, reduce five ghost shrimp.

3. The General Condition Of The Filtration System

Ghost shrimp are not quite as messy as other creatures. In fact, they improve the hygiene of aquariums by eating dead and decaying matter, as I discussed here. But again, the presence of other creatures matters.

The more aquatic animals you have, the more waste they produce, the more powerful the filtration system you need. You can’t rely on ghost shrimp to eat all the pollutants in a tank.

If you don’t have the financial means to buy a more powerful filter, you should keep fewer ghost shrimp. If you don’t want to reduce your ghost shrimp population, maintain a shrimp-only tank.

In case your aquarium isn’t properly filtrated or you have a lot of debris in your tank, reduce the number of ghost shrimp mentioned above by half. Once you improve the filtration, you can add more shrimp or fish.

4. The Types Of The Aquarium Tankmates

The temperament of the fish in the tank is crucial. If your ghost shrimp have aggressive tankmates, you have to add more plants and decorations to keep them safe.

If the tankmates are social and friendly, you can afford to maintain fewer plants and decorations in the aquarium, which, in turn, allows you to add more ghost shrimp.

For your convenience, here is an article where I discussed what fish can live with ghost shrimp. If your tank features any of the listed fish, avoid adding ghost shrimp by all means. I also dedicated an entire article to what shrimp can live with ghost shrimp.

Do You Need More Than One Ghost Shrimp?

Ghost shrimp are social creatures that can live peacefully with one another. However, you don’t have to keep them in groups. Unlike some fish, they can live alone. They don’t have to live in a community to thrive.

Ghost shrimp won’t grow bored, lonely, or miserable if kept alone. If the conditions in their tank are suitable, they will survive. The only reason to keep multiple shrimp in the same tank is to breed them.

The female shrimp will lay the eggs, but you need the male shrimp to fertilize them. If you don’t want to breed the shrimp, you can get by with one ghost shrimp in a tank.

How Many Ghost Shrimp Does It Take To Start A Colony?

It takes ten ghost shrimp to start a colony. Ideally, it is best to keep two females for every male ghost shrimp. Ghost shrimp are not particularly difficult to breed. Your only role is to add at least one male and female shrimp to a tank with proper water conditions.

Technically, to start a ghost shrimp colony, all you need is one male shrimp and one female shrimp.^[4] Ghost shrimp do not have to live in groups to thrive. But it is more common for aquarists to start with 5, 10, or even 15 ghost shrimp.

How Do You Grow Multiple Ghost Shrimp In A Single Tank?

As suggested earlier, when starting a ghost shrimp colony, the first step would be choosing the proper number of ghost shrimp for your aquarium. However, I also suggest that you adjust the water parameters.

Even when kept in the correct numbers with the proper tankmates, your ghost shrimp will fail to survive and reproduce when the water conditions are wrong.

These are the ideal water parameters for ghost shrimp:^[5]

Temperature: 65°-75°F (18.3°-23.8°C)
pH: 7.0-8.0

GH: 3-10 dGH (50-166.7 ppm)
KH: 3-15 dKH (53.6-268 ppm)
Ammonia: 0 ppm

Nitrites: 0 ppm
Nitrates: <20 ppm

As for the temperature, ghost shrimp don’t require a heater. The room temperature is usually enough. Actually, subtle swings between day and night work in your favor because it mimics the ghost shrimp’s natural habitat.^[6]

To measure the pH, ammonia, nitrates, and nitrites, I personally use the API Water Test Kit (link to Amazon). That is probably my favorite because it lasts for about eight hundred measures, making it highly cost-effective.

If any of the toxins are too high or the pH is too low, I recommend making more frequent water changes. As a rule of thumb, I replace 15 to 20 percent of the water weekly. Then, consider adding API Quick Start Nitrifying Bacteria (link to Amazon) to your aquarium.

To measure the water hardness, I use this API TEST KIT (link to Amazon). It comes with two bottles containing GH and KH testing solutions. If the numbers you get fall out of the desired range, consider changing your water source.

What To Do With Too Many Ghost Shrimp?

Ghost shrimp breed quickly and easily. The females can lay hundreds of eggs at once, hatching within 24 hours. That means that these creatures can easily overwhelm your aquarium.

But you cannot allow crowded conditions to become the norm. Besides the stress it induces in shrimp, overcrowding attracts oxygen deficiencies. The ghost shrimp will consume the oxygen faster than the tank can replenish it.

Additionally, you can’t maintain an overcrowded tank, not for long. Because of their size and penchant for eating dead and decaying matter, ghost shrimp are not messy creatures.

But if you have hundreds of shrimp within a small space, they will produce more than enough waste to ruin the water’s chemical balance.

Fortunately, you have several solutions at your disposal. Some effective methods of reducing the ghost shrimp population in your aquarium include:

1. Add A Few Predators

Add fish that eat ghost shrimp. That includes goldfish, discus, cichlids, gourami, and more. Any aggressive species that is larger than the shrimp will do. The number of predators added will depend on your objectives.

Don’t saturate the tank with aggressive species unless you want them to eat all your shrimp. Limit the number to two or three goldfish, depending on the size of your tank.

Predators are the simplest solution because they don’t require your direct involvement. Once you add the predators, you can sit back and wait for them to do their work.

It should be noted that ‘Ghost Shrimp’ is a broad term that refers to numerous species. The most common type of ghost shrimp has a larvae stage that can only survive in brackish water.

If you want to breed ghost shrimp in brackish water but don’t want their numbers to run out of control, look for aggressive brackish water fish such as puffers and archerfish.^[7]

2. Consider A Larger Tank

Don’t be so quick to kill your excess shrimp. Where possible, get a bigger tank. Large populations of ghost shrimp are only problematic if their tank is too small.

But if you can house them in a larger tank, they can survive and thrive without ruining the conditions in their aquatic environment. Larger tanks are easier to maintain because it takes longer to pollute them.

3. Separate Males And Females

A bigger tank is not always the answer. If the shrimp are multiplying uncontrollably, they will probably outgrow the new tank. Unless you have the money and patience to buy another tank down the line, you are better off preventing the shrimp from reproducing in the first place.

They can’t reproduce unless you have a male and female shrimp. The female ghost shrimp lays the eggs, and the male shrimp fertilizes them. Therefore, you can move one gender to a separate tank. This will put a stop to the reproduction process.

Here is an excellent Youtube video that will help you identify the gender of your shrimp:

4. Sell Your Ghost Shrimp To Fish Stores

Separating the genders won’t help you if you already have excess shrimp. Fortunately, fish stores will happily buy them from you, especially if your prices are low. If you don’t have any fish stores in your area, use the internet to find aquarists that want ghost shrimp.

If you can’t find a willing buyer, give them away. If you have friends and family that rear fish, they will appreciate the ghost shrimp once they learn that the creatures are tank cleaners.

5. Use The Ghost Shrimp As A Food Source

Another solution is to feed the shrimp to your fish. If you have a second tank with carnivorous and omnivorous fish, the shrimp can supplement their diet. People that use this option usually encourage their ghost shrimp to reproduce.

They use the ghost shrimp tank as a meat farm for their fish. Many beginners are tempted to flush their excess shrimp down the toilet. But that practice is dangerous because it can have disastrous consequences for the local ecosystem.

If you found this article helpful, these may also interest you:

What Do Ghost Shrimp Do In Tanks? (5 Surprising Facts)

How To Hatch Ghost Shrimp Eggs: 5 Simple Steps

Conclusions

As a rule of thumb, you can keep five ghost shrimp for every gallon of water. However, bear in mind that ghost shrimp multiply rapidly. Therefore, I suggest starting small and increasing your shrimp numbers slowly.

You should also consider vegetation and other tankmates, as these will lower the recommended amount of ghost shrimp. Lastly, do not forget to keep a close eye on the water conditions. That includes the pH, temperature, toxins, and water hardness.

References

https://www.aqueon.com/resources/care-guides/brackish