When and How to Upgrade to a Larger Tank

There may come a day throughout your journey as an aquarium hobbyist that it becomes necessary to upgrade your existing tank to a larger tank but how do you know when you’ve reached this point? There are a variety of factors that should be considered when making the decision to upgrade to a larger tank – it is not something you should do on a whim. In the same way you probably performed some research and made preparations when setting up your first freshwater tank, upgrading your tank will take some careful consideration, planning and preparation.

Factors Contributing to the Need for Upgrades

There are several valid reasons why you might decide to upgrade your freshwater tank but perhaps the most important reason is for the health and safety of your fish. Many novice aquarium hobbyists make the mistake of purchasing juvenile specimens of large species like Oscars and other cichlids, not realizing just how large these fish can get. If you make the mistake of placing an Oscar in a 30-gallon tank, it won’t be long before you either need to re-home your fish or upgrade the tank. Not only is the size of your fish a factor but the number of fish in your tank could also contribute to the need for an upgrade. If you have a community tank housing a large number of fish, particularly species that breed readily in community settings, you could soon have more fish than your existing tank can accommodate.

Another reason aquarium hobbyists might choose to upgrade to a larger tank is simply for the challenge of it. Many aquarium hobbyists start out with a 20- or 30-gallon tank which is a perfectly manageable size. After you get the hang of keeping an aquarium, however, you might feel like you are ready to take on a little more responsibility. Upgrading to a larger tank gives you the opportunity to experiment with new decorations and set-ups while also giving you the option to keep larger species of fish.

Preparing for the Upgrade

Once you have made the decision to upgrade your tank you need to think carefully about what size tank would be best. Think about what type of environment you want to cultivate along with the species and number of fish you intend to raise. Once you have selected a tank you then need to consider your tank equipment – the filter, heater and lighting system you have in place in your existing tank may not be appropriate for a larger tank. If you do need to purchase new equipment, be sure to perform some research to find a reliable model and select one that is rated for your particular tank size. You may also want to consider purchasing some new decor items for your upgraded tank including some live plants to help keep the oxygen level in your tank water high.

Step-by-Step Instructions for Upgrades

1. Siphon the gravel in your existing tank using an aquarium vacuum to remove the bulk of accumulated waste and uneaten fish food.
2. Relocate your fish to a quarantine tank, if possible, to avoid putting them under any stress during the process of upgrading your tank.
3. Fill the new tank with as much water from the existing tank as possible and transfer the gravel from your existing tank to the new tank as well. Beneficial bacteria responsible for maintaining the nitrogen cycle in your tank are most heavily concentrated in the substrate but they can also be found in your tank water. By transferring some of your substrate and tank water to the new tank, you can greatly reduce the amount of time it takes your new tank to cycle.
4. Set up your aquarium heater, filter and lighting system in the new tank and plug them in to be sure they work. Let the heater and filter run for a full 24 hours before you continue setting up the tank. This should give your tank temperature time to stabilize.

5. Add your decorations to the tank and fill the tank the rest of the way with fresh tap water. Dose the water with an aquarium conditioner to remove chlorine and other chemicals your water may have been treated with.
6. Let the tank run for another 24 hours then test the water using an aquarium water test kit. When evaluating the results of the test you should pay particular attention to the levels of ammonia, nitrate and nitrite. As your tank cycles, the beneficial bacteria in your tank will convert ammonia into nitrite and then into nitrate.
7. Test your tank water once a day as it cycles. When the test registers a zero level reading for ammonia and nitrate and it begins to pick up a nitrite level it is safe to assume the tank has cycled.
8. Introduce your fish into their new aquarium as carefully as possible to avoid putting them under any stress.
Additional Tips

Once you have gotten your new tank set up and your aquarium fish have been re-introduced, you can simply carry on in your regular routine for maintaining your tank. It may take a little time to get used to the maintenance requirements and care of your new tank but it shouldn’t be vastly different from what you are used to. As long as you keep up with your routine water changes, you should have no trouble keeping your new tank clean and clear.