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Here are 10 Stocking Ideas for 5, 10 and 20 Gallon Fish Tanks

Originally, this list was built for college fish keepers, but anyone can take these suggestions and run with them!

So you're moving onto campus to start your next semester in college and you want to bring a fishy friend to keep you company for those inevitable all-nighters, but don't know what fish to choose? Well stay tuned, I have 10 suggestions down below!


As I built this list, I kept a few assumptions/disclaimers in mind since my target audience is college fish keepers:

  1. You are relatively new to the hobby with minimal experience.

  2. Your college/university policy accepts anywhere between 2.5 to 20 gallon tanks on campus.

  3. This list is by no means conclusive or comprehensive. This list is based more on availability and my personal preference.

  4. This is not a full care a guide, but more of a starting point for you to choose from. Once you decide which stocking options may be right for you, always remember to research more!

why it's important to pick the right fish

  1. Size of tank - Picking the right stocking given your tank size is important for the health and wellbeing of your fish

  2. Maintenance - Since this list is for college students, I tried to build this list keeping in mind minimal maintenance. The more overstocked your tank is, the more maintenance you need to do. Understocking can create some cushion for you, just in case you're not be able to keep up with maintenance due to breaks, homework or final's week.

  3. Hardiness - While this should never be an excuse to slack off on your fish care. The more hardy your fish is the better, especially for those of you first entering the hobby.

  4. Reproduction - Some fish reproduce quite often (i.e. livebearers). Ideally you want to avoid fish with high reproductive potential, especially if you're in a dorm because your tank can be overrun at the blink of an eye.

2.5 gallon tank ideas

0. Plants

Plants accomplish many things that fish keepers look for in the hobby:

  • They provide a sense of responsibility

  • You get the satisfaction of seeing them grow over time with appropriate care

  • They make your tank look aesthetically pleasing

While some types require good lighting, CO2, and/or fertilizer, they require minimal effort relative to live fish. Plants are a great starting point into the hobby.

1. Snails

Generally, you have two options when it comes to snails: mystery snails or nerite snails.

Mystery snails:

  • Need a lid because they are known to be escape artists

  • Are generally bigger than nerites

  • Can lay clutches of eggs right above your tank's water line

  • Sometimes eat live plants

Nerite snails:

  • Lay singular eggs all throughout the tank

  • Smaller than mystery snails

  • Come in many unique patterns (i.e. zebra, tiger, olive, horn)

  • Less likely to eat live plants

When it comes down to it, you cannot go wrong with either. I personally keep both, but I like Nerite snails because of the various designs they come in. My one advice is to avoid those pesky pest snails that you may see in some plants from your local fish store. Since they can reproduce asexually, they can be a real pain!

2. Red Cherry Shrimp (Neocaradina)

Red cherry shrimp are really interesting to watch and are pretty easy to take care of. You can even pick from a various assortment of colors. You can go with neocarardina or caradina shrimp. Ease of care for either really depends on how your local tap water naturally comes from the faucet. Neocaradinas do better in harder water, whereas caradinas do better in softer water.

Some other options include amano shrimp and ghost shrimp. Amano shrimp are also beginner friendly, though they can get pretty big relative to other the aforementioned shrimps, so keep that in mind. Ghost shrimp (palaemonetes sp.) are also a good option because they are hardy and easy to find in pet stores.

5 gallon tank ideas

3. Betta splendens

I'm sure you saw this one coming. Betta splendens are great beginner fish for a plethora of reasons. They come in many colors, sizes, shapes, and personalities. You really can't go wrong with a betta. If you're lucky, you can find one that's chilling enough to have tankmates! Note, if you go for a giant betta, the minimum tank size I would advice would be a 10 gallon tank.

4. All male endler guppies

As stated earlier, the last thing you want to do is have breeding occur in a 5 gallon tank. Endlers and guppies are known to reproduce like crazy in a short amount of time. I recommend you get 2-3 males instead. You can get 2-3 females, but males usually come in more interesting colors. In my experience, livebearers aren't nearly as hardy at bettas, but I guess that really depends on which breeders you get your endlers from.

10-20 gallon tank ideas

5. honey Gouramis

Honey gouramis make a great center-piece fish in any community tank due to their lack of aggression. They can be kept in groups, pairs, or solo. Keep in mind, they can get up to 2.5-3 inches in length, so I wouldn't go any less than 10 gallon tank. Nonetheless, they are a beautiful option that can work with many different fish.

6. Neon or Cardinal tetras

Tetras come in many shapes and sizes. They are popular in the hobby due to their schooling behavior. With that being said, I highly recommend you keep these in groups of at least 6. Any less would be non-ideal since they're use to being in schools. I personally prefer cardinals over neons due to the slightly longer red strip, but you can't go wrong with either! Other options to consider include green tetras and ember tetras.

7. Chilli Rasboras

Chilli rasboras are tiny little fish that make a great addition to any community tank. They usually stay less than an inch and are generally not shy, despite their size. Similar to tetras, I would keep a minimum of 6 together.

8. Celestial pearl danios

Unlike chilli rasboras, celestial pearl danios are more likely to be skiddish. But they are very peaceful, which is always a good quality to have. Rather than schooling, celestial pearl danios shoal. Under the right light, you can see their great coloration. They may not be the most hardy, so always shoot to get them from a local fish store with good sources or a good breeder.

9. Pygmy corydoras

Pygmy corydoras are CORYDORABLE... sorry I'll just leave now.

Anyway, they really are cute little fish. Maxing out at about 1 inch in length, they still pack in a bunch of personality. A unique thing I like about pygmy corydoras is they often swim in the mid-layer. Like tetras, they prefer to be in groups and do show some schooling behavior. Thus, I would keep a minimum of 7 together.

10. male and female guppies, platys, or mollies

Live bearers are always a fun time given how highly reproductive they are. If you're going for a 20 gallon tank, you can definitely keep males and females together. I personally recommend you get 3 females to 1 male, so as not to overwhelm the females. You never want to have more males than females because the females might not thrive due to the constant stress of those jackrabbit males. Just remember to have plan of what to do with the babies, because they will inevitably multiply within months. One thing to be weary of is livebearer disease, so do your research!

fish to Avoid

Keeping in mind a tank size ranging from 2.5 to 20 gallons, there are a few fish that I would highly recommend you avoid. These fish are commonly bought at a small size without first-time owners knowing how big they truly get. I would avoid gold fish, angel fish, and common plecos.

Community Tanks

As you look at the list and explore your options, one thing you can consider is a community tank. Of course, this is more ideal for 20 gallon tanks and bigger, so keep that in mind. A great tool to use to see if you would be overstocking your tank or not would be


Hopefully this was helpful! I think keeping a tank while on campus has a number of benefits and I would highly recommend it, so as long as you do your due diligence. Enjoy and welcome to the hobby!

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Hi! If you're looking for a place of informational integrity, you're at the right place! My name is Harry, I'm a Pharmacist with a love for fish keeping and the aquarium hobby. I'm not the most experienced fishtuber/fish keeper out there, but if there is one thing pharmacy school taught me, it's how to learn, diligently and efficiently. My mission is to address the misinformation and lack of accessibility of accurate information in the fish keeping hobby through tips, tricks, reviews and research-based best practices.

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