10 Smart Ways to use an Aquarium Catch Cup Or Specimen Container


10 Smart Ways to Use an Aquarium Catch Cup or Specimen Container

Have you ever seen those clear rectangle boxes hanging on the outside of tanks at your local fish store? The aquarium specimen container, or catch cup, is one of the most useful tools in fish keeping. It is a transparent, small container that can be used to observe fish or hold aquarium supplies. Discover the top 10 uses for catch cups in our personal fish tanks and at our retail fish market.


1. Observation

It can be hard to really see your fish when they are zooming around an aquarium or darting behind decorations, so to get a closer look, catch a group of them with a fish net and place them in a catch cup full of water. The smaller space allows you to inspect the fish for disease symptoms, pick the healthiest individuals for breeding, or sort out male and female juveniles for sale. You can also use the flat, clear walls to take photos of your favorite species.

2. Transportation

While aquarium nets can be used to move a few fish between tanks, this method is not efficient if there are many fish to move. Instead, use your specimen container as a temporary holding pen until you finish catching all of them and then move them together afterwards. You can relocate fry to a grow-out tank to prevent them from getting eaten by predators, bring pond fish indoors for the winter, or remove pest snails in one tank to feed to your pufferfish aquarium.

3. Selling fish

Fish bags are required if you plan to sell your fish at an auction, fish shop, or online. Place the fish in the container. Once you have enough fish to go around, place them in a fish bag. Seal them with rubber bands. Multiple containers can be used – one container to hold large quantities of fish, and another to separate the species and numbers for each bag.

4. Acclimation

If you are buying new fish or shrimp, they may be accustomed to water parameters that are very different from yours, and therefore you may want to slowly acclimate or get them used to your aquarium water. You can also acclimate small animals in the specimen container.

1. Cut open the fish bag and pour the animals and some of the water from the bag into the catch cup so the fish are completely covered in water. 2. The catch cup should be filled with aquarium water. (If the water gets too high, just pour some out of the container.) 3. After 15 minutes, add more aquarium water so the water is doubled again. 4. After 10 minutes add more aquarium water until the water has doubled. 5. Net the fish out of the container and add them to the aquarium.

You can also do drip acclimation using lengths of airline tubing. This is a slower process. If fish are racing around in the catch container, you can help calm them by making the room darker and/or covering it with a towel.

5. Breeding

An air stone, check valve and airline tubing can be added to your DIY breeder box. Keep the specimen container in the aquarium to keep it warm. Add the air stone to ensure the fish have enough oxygen. Then you can place a select pair of fish inside to increase the chances that a certain male and female will mate together. This simple setup can also be used to hatch fish eggs that need a few drops of methylene blue to prevent fungal growth. You can also temporarily raise your newborn fry in a catch container without worrying about them (or any small foods they eat) escaping. Add a clump of java moss or other live plants to give them shelter, and make sure to frequently clean out the dirty water inside using a turkey baster.

6. Isolation

In some cases, you might need to temporarily remove one fish from others. A calm and peaceful environment is helpful for female guppies, mollies or other livebearers about to give birth. The “birthing area” will prevent the fry being eaten immediately by larger fish and will also help the infants hide from their mother.

A fish suffering from an injury, behaving strangely or displaying other unusual symptoms could be isolated. You can monitor their condition and possibly treat them with medication by keeping them in an airstone-enclosed container. The full article contains more information about treatment of fish diseases.

7. Mealtime

We always recommend feeding many different fish foods to ensure your fish get a variety of essential nutrients, but it can be hard to juggle all those round jars and slippery packages. Your catch cup can be used as a food container to transport everything from one tank to the next. To feed frozen foods, you can thaw the cubes inside the container. Then use a turkey baster or pipette to pour the liquid into multiple aquariums. The same technique can also be used with live fish foods like baby brine shrimp, blackworms, daphnia, and infusoria.

8. Water Transfers

As mentioned before, the catch cup is like a mini bucket, so we often find ourselves using it to quickly remove surface scum from an aquarium or replace water that has evaporated from a nano tank. If you want to test your water parameters using liquid reagents, scoop up some tank water with the specimen container and then use a pipette to fill the test tubes. During water changes, some hobbyists will place their catch cups inside the aquarium and then stick the end of the hose or aim their Python hook into the container while refilling the fish tank. The incoming water gently overflows out of the catch cup, preventing your plants and substrate from being disturbed by the force of the faucet.

9. Equipment Storage

If you use fish nets, alga scrubbers, or any other tool in your aquarium, a specimen container can be used to keep them from dripping all over the floor. A lot of people hang the catch cups on the side to save space and keep their fish food, fertilizers, or other supplies easily accessible.

10. Planted Tank Maintenance

We love using specimen containers for the maintenance of our planted aquariums. They can be used to remove unwanted floating plants like duckweed from your aquarium. To propagate your stem plants, place the trimmings of the stem plants in the catch cup.

Now that you know you need to have a specimen container in your life, make sure to get the Aquarium Co-Op Catch Cup. The walls are extremely clear to allow you to see your fish and the plastic is shatter-resistant so it won’t fall if dropped. The extra-wide handle makes it easy to hang on fish tanks with thick walls.