If you’re looking for an aquarium setup that’s easy to care for, cold water tanks are a great option. They do not require heaters, and they’re a little easier to maintain.
Here’s everything you need to know about setting up a cold water aquarium and 15 of the best fish to stock it with.
Table of Contents
The first thing you need is a tank. Most tanks come with a starter kit with everything you need, or you can buy all the pieces separately. You will need a filter that’s the appropriate size for your tank and an air pump.
If you buy a kit, make sure it is for a cold water setup. Most kits include heaters, which you won’t need. Other things to have on hand are a net, water conditioner, and algae scraper.
One important thing to consider is the size of the tank. This is an important decision because it directly affects the type and number of fish you can stock it with. Generally, it’s a good idea to get the largest size that you can comfortably afford. The larger the tank, the more options you have.
After you have the essentials, it’s time to think about how you want to decorate your tank. There are many types and colors of substrate available, as well as plants and natural-looking decor. If you choose plants for your cold water tank, do some research first to make sure they can survive in cooler temperatures.
Cycling the Tank
Cycling is the most important part of setting up any aquarium. Basically, cycling is the process that allows enough beneficial bacteria to grow in the tank to effectively break down the waste from the fish and other detritus.
If the tank is not cycled properly, ammonia, nitrate, and nitrite build up in the water, potentially killing the fish. If you’ve ever added fish to an aquarium only to have them all die a week or so later, it’s likely the tank wasn’t adequately cycled.
The cycling process can take as many as eight weeks or more, so don’t plan on adding all of your fish right away. You will need a water testing kit to determine when the tank is ready. There are many ways to cycle a tank, so make sure you do your research and choose the one that works best for you.
Stocking the Tank
There are a lot of options for stocking a cold water tank. Here are 15 of the most popular.
1. Cherry Shrimp
This dwarf shrimp variety is popular for its bright red color. They’re fun to watch and easy to care for. Plus, they can tolerate temperatures as low as 57 degrees F, so they’re perfect for a cold water tank.
Cherry shrimp are sensitive to nitrate and nitrites so make sure your tank is properly cycled before adding them. They like to be kept in groups of five or more, and they only grow to be about a half-inch long.
Although they’re peaceful and can coexist with a lot of different types of fish, cherry shrimp do like to have places to hide. Make sure there are plants, pieces of driftwood, and java moss to keep them happy. Cherry shrimp are scavengers, too, so they’ll help keep the bottom of your tank clean.
2. White Cloud Minnow
White cloud minnows are a good choice for cold water tanks and great fish for beginners. In the wild, they live in shallow streams with a moderate amount of vegetation. They like some water movement and need a 15-gallon tank, minimum.
These fish prefer to live in groups of six or more and like their tank to resemble their natural habitat. A dark, sandy substrate with some small rocks and pebbles and clumps of plants is ideal. These fish are carnivorous, so don’t put them with smaller fish as they’re likely to eat them.
White cloud minnows grow to about two inches long and like a water temperature between 64 and 72 degrees F.
3. Bloodfin Tetra
If you have a smaller 10-gallon tank, bloodfin tetras are a good choice. They like water that’s between 72 and 78 degrees F and can grow to about two inches long. Bloodfin tetras should live in shoals of at least six as they do not do as well when kept in small groups.
These fish are some of the most popular for beginners and are available just about anywhere. They’re fast, colorful, and fun to watch.
4. Zebra Danio
Zebra danios are fun to watch and a nice addition to a cold water tank. They prefer temperatures between 65 and 75 degrees and need at least 20 gallons because they prefer to live in groups of six to eight.
This is a great choice for beginners because they’re easy to care for and fun to watch. They love to explore and enjoy plants, caves, and driftwood, but they should have a nice open space in the center of the tank to swim freely.
5. Paradise Fish
Paradise fish are labyrinth fish, meaning they have an organ called a labyrinth that allows them to breathe both water and air. They can tolerate temps as low as 50 degrees F or as warm as 71. They prefer a long planted tank with driftwood and floating plants.
Males are territorial and shouldn’t be kept with other males because they will fight. The best combination is a trio of two females and a male. They get along well white cloud minnows and can grow to about four inches long.
6. Red Rosy Minnow
This is one of the easiest to care for cold-water fish. Red rosy minnows can tolerate temperatures as cold as 50 degrees F and are extremely hardy. In nature, they can be found just about everywhere, from murky or muddy water to clear-running streams.
Red rosy minnows have a pinky-orange color that stands out well in most tank setups. They aren’t picky about what goes in their tank, but they do like a little open space to swim. In fact, this is one of the reasons they make a great pond fish, too.
One thing to keep in mind about red rosy minnows is that they’re usually used as feeder fish, so they’re not always kept in the cleanest conditions. Get them from a reputable shop so you know they’re healthy.
Tankmates can be tricky because a lot of species see red rosy minnows as food. Large and aggressive species are not a good fit, but they get along well with loaches, shrimp, and some types of goldfish.
7. Asian Stone Catfish
Asian stone catfish are small, only growing to about 1.5 inches long. They’re schooling fish, though, so you should keep five or more together. This is one of the few fish that’s suited to live in a small ten-gallon tank, so if you don’t have the budget for something bigger, you’re in luck.
This fish is happy in water temperatures between 60 and 75 degrees f. Because this fish is so small, you have to be careful about tankmates. Give it a sandy substrate with a lot of plants and decorations so it has a lot of safe hiding places.
8. Hillstream Loach
This is a small fish that normally lives in rivers in South China. They prefer habitats that recreate their natural environment and need large tanks of 45 gallons or more. Go with a sandy substrate with small gravel or stones to recreate their natural habitat. As for water temperature, they prefer anywhere from 68 to 75 degrees F.
A tank with Hillstream loaches should have a moderate to strong current, and the water quality has to be maintained well. With the right care, these fish grow to about three inches in length and can live as long as eight years.
Hillstream loaches are bottom feeders and usually live off of algae, so they’re a great way to control algae growth in a tank, too. They also like brine shrimp and bloodworms. These fish don’t need a planted tank, but fiddleheads and anubias are good options if you want to plant some.
9. Gulf Coast Pygmy Sunfish
If you’re looking for a cold-water fish that’s appropriate for a nano tank, check out the Gulf Coast pygmy sunfish. These fish only grow to about one-inch long and thrive in water temperatures between 60 and 75 degrees.
Caring for this fish is really easy. It isn’t picky about water parameters and can cope with lower oxygen levels. They prefer calm, heavily planted tanks. This species can be picky eaters, but they usually settle for insects and micro-worms, always preferring live food to frozen or prepared.
10. Sunset Platy
Sunset platys are easy to care for and do well in a variety of conditions, tolerating water as cold as 64 degrees F. They’re peaceful, friendly, and a great addition to community tanks. That said, they can be aggressive as males tend to harass females, so try to keep males outnumbered two to one.
Platys love a planted tank with lots of places to hide and explore, and this variety is particularly pretty to look at. Their bright yellow, orange, and reds bring pops of color to any tank. They can grow to about 2.5 inches long and need a minimum of 15 gallons.
11. Fancy Goldfish
It’s no surprise that fancy goldfish are one of the most popular cold-water fish. They’re fun to watch, gorgeous, and tolerate water temperatures between 62 to 72 degrees.
You’ll need a tank of at least 20 gallons with efficient filtration because these fish are messy. Water changes of about 50 to 60 percent are needed every week.
Fancy goldfish can grow to about 10 inches in length. They’re peaceful and get along with other fish, but aggressive tank mates should be avoided because they will likely nip at the goldfish’s fins.
12. Bristlenose Pleco
Bristlenose plecos are adaptable and can be kept in a variety of different environments. They tolerate temperatures between 60 to 80 degrees F and need a tank that’s at least 25 gallons. This is a cool-looking fish with bristles around the mouth that kind of looks like a mustache.
Plecos have mouths on the bottom of their bodies and cling to the substrate and the walls of their tanks, devouring algae. Their bodies are covered in plates, too, so they’re protected from aggressive tank mates or natural predators.
These fish grow to about five inches long and are easy to care for. This is a good choice for beginners.
13. Weather Loach
If you have a tank that’s 40 gallons or more, consider adding a weather loach to your tank. These fish are hardy and peaceful, and they can thrive in temperatures between 55 and 77 degrees F. They can grow to 12 inches long, so make sure you give them enough room to grow.
Weather loaches do well in large community tanks. They love to hide in rocks and tubes and prefer sand or fine gravel as a substrate. They’re friendly and will even willingly take food from their owner’s hand.
14. Rosy Barb
Rosy barbs can get up to six inches long in the wild. They prefer to live in groups of five or more and need a tank that’s at least 30 gallons and 64 to 72 degrees F. They’re active fish that can live for up to five years and like to hang out in the middle of the tank.
This fish gets its name from its coloring. Males are usually brighter red while females are more gold or silver. Both sexes have long, thin bodies with forked tails and black markings on the sides and fins.
Generally, rosy barbs are pretty friendly, but they can nip at fins. Keeping them in groups can help control this behavior, but they shouldn’t be kept with long-finned fish. Rosy barbs are hardy and easy to care for, but make sure you keep a lid on your tank because they do like to jump.
15. Dwarf Crayfish
Dwarf crayfish look like tiny lobsters and are a cool addition to a cold water tank. They need at least 10 to 20 gallons and prefer a water temperature between 60 to 75 degrees F. Dwarf crayfish are peaceful and usually grow to about one inch long.
These fish are omnivores and prefer to eat bloodworms, mosquito larvae, algae pellets, and peas. They love a little place to hide from the rest of their tankmates, but they are pretty active and fun to watch.
Dwarf crayfish molt, so don’t be surprised if you see an empty shell in your aquarium even so often. One thing to keep in mind about dwarf crayfish is that they are extremely sensitive to nitrates and nitrites, so they should never be placed in a tank that isn’t properly cycled.
So Many Choices
As you can see, there are a lot of options out there for stocking a cold water aquarium. We included a wide range so that you can find the perfect fish for your set up, no matter what the size of your tank.
Fish are very relaxing and beautiful to look at and many species are kept for these reasons. They are suitable pets for people living in flats or other confined areas, but for people with plenty of outdoor space an in-ground fishpond can enhance a garden setting. Whether kept in an aquarium or pond, a great deal of care is required in looking after fish properly in terms of facilities, time, financial means and level of interest. Particular attention must be given to water surface area, temperature control and water quality.