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Different Aquarium Water Flow Rate Requirements

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    Fish tank water movement is a very important aspect of each aquarium system. Many different animals and plants have different water movement requirements and it is important to appeal to each one. For example, seahorses require fish tanks with a slower flow rate because of their sluggish eating habits and very slow, gentle movements. Also, plants require slower flow in freshwater aquarium systems because too high a flow can damage the plants. This article will discuss different flow rate requirements for common aquarium systems. It will also discuss different ways to introduce water flow in an aquarium.

    Standard Aquariums

    It is common for beginner aquarium keepers to set up a “standard” styled aquarium. Many of these aquariums are filled with plastic, clay, and ceramic decorations to beautify the fish tank. Regardless of what decor is added, this type of fish tank still requires water flow and water movement for it to prosper. It is recommended to turn over your water through your filter at least four times every hour. For example, if you own a 10-gallon tank, at the minimum, 40 gallons of water should flow through your filter every hour. Luckily, equipment that moves water will also provide a gallons per hour (GPH) rate, so usually no calculations are needed.

    Hang on Back Filter

    Standard-styled aquariums can reach proper water flow and water movement rates in different ways. One of the most common equipment used for smaller aquariums is hang on back (HOB) filters. As its name suggests, this filter sits on the rim of your aquarium and filters water. Most hang on back filter vendors will provide a GPH turnover rate, which is often labeled on the box.

    If the appropriate filter is chosen, it should provide the proper amount of oxygenation and flow for the aquarium. As a reminder, GPH rates labeled on the box are tested at optimum conditions. The filters are likely tested without any filter media and at full speed. In an aquarium setting, these conditions will probably not be met because you will probably fill your filter with different types of media. I personally almost always recommend a hang on back filter for new aquarium keepers because it provides Mechanical, Bacterial, and chemical filtration all in one. If you’re shopping around for different hang on back filters, check out 7 Best Hang on Back Power Filters for Freshwater Aquariums.

    Sponge Filter

    The main limitation of sponge filters is that they only provide bacterial filtration. However, you can still achieve proper water movement rates with a sponge filter. Sponge filters connect to air pumps through airline hosing. The air pump brings large oxygen bubbles into the aquarium. The bubbles float to the top of the aquarium and cause a disturbance on the water’s surface. The disturbance in water brings oxygen into the aquarium from the air. The movement of air and water creates water circulation throughout the whole tank. Using sponge filters, the proper water flow rate is easy to achieve in smaller aquariums but may be more challenging in larger fish tanks. You can learn more about sponge filters by taking a look at Sponge Filters Use, Cleaning, and Extra Tips!

    Other Ways To Acquire Good Flow Rates

    There are other ways to achieve proper flow rates not only in standard aquariums but other aquariums too. You can use powerheads (circulation pumps) to move water around the aquarium. These pumps do not provide filtration. They only move large amounts of water around. You can learn if your aquarium will benefit from having a circulation pump by checking out Do I Need a Circulation Pump For My Aquarium?

    Although these filter types are not very common, you can connect an air pump to an undergravel filter. This will provide water movement and filtration. You can also use canister filters, sumps systems, and submersible filters to filter your aquarium and provide water movement. Larger aquariums commonly use canister filters and/or sump systems.

    Planted Aquariums

    Like standard aquarium setups planted aquariums can use filtration systems such as hang on the back, sponge, and all the other types besides undergravel filters. However, larger planted aquariums will more than likely use a canister filter or a sump system to acquire proper water flow rates. Each has its advantages and disadvantages and I will go over both. If you’re setting up smaller aquariums, take a look at the information provided above to learn about sponge filters and hang on back filtration systems.

    Canister Filters

    Canister filters are an excellent way to filter and add water flow to your planted aquarium. Just like other filtration systems, the canister filter flow rate should be labeled on the packaging provided. As stated above, your fish tank should have a water turnover rate of roughly 4x the total gallon amount every hour. To continue, canister filters provide chemical, biological, and mechanical filtration. Each of these is important for a successful aquarium setup. However, canister filters are a little different than other filtrations. This filter minimizes the contact water has with surface air.

    This is great for planted aquariums because there is less oxygen exchange between water and air. Something like a sump system increases oxygen exchange with air and water and might require you to supplement more carbon dioxide. Also, canister filters are usually nice and compact. You can fit quite a bit of filter media, sponges, and more. They’re great for aquarium keepers with little space.

    Disadvantages of Canister Filters

    One of the main disadvantages of canister filters is the maintenance around it. Overall, maintenance is not too terrible and filter technology has made maintenance easier but it can be a chore. You have to remove the canister filter, drain the water, open it up, remove the media, replace it, and then put it back together again. Moving a big bulky filter can be challenging so keep that in mind when choosing filtration systems. Also, when choosing filters, make sure the brand you use is reliable. Although it’s not common, like any piece of equipment, canister filters can malfunction and leak water. Buying canister filters from a reliable brand like Fluval helps decrease the chance of leaking.

    One of the main disadvantages of canister filters is the maintenance around it. Overall, maintenance is not too terrible and filter technology has made maintenance easier but it can be a chore. You have to remove the canister filter, drain the water, open it up remove the media, replace it, and then put it back together again. Moving a big bulky filter can be challenging so keep that in mind when choosing filtration systems. Also, when choosing filters, make sure the brand you use is reliable. Although it’s not common, like any piece of equipment, canister filters can malfunction and leak water. Buying canister filters from a reliable brand like Fluval, helps decrease the chance of leaking.

    Do not let this deter you from considering canister filters as your filtration system. They’re an excellent type of filtration that packs a punch in keeping your fish tank clear and clean. If you feel canister filters aren’t for you, consider setting up a sump system for larger planted tanks. I will discuss the pros and cons of sump systems in the saltwater aquarium section.

    Saltwater Aquariums

    Smaller saltwater aquariums will commonly use HOB and/or sponge filters providing flow and filtration. An addition of powerheads/circulation pumps is almost required in saltwater fish tanks. Overall, saltwater aquariums are unique because of the vast differences in animals that live in these systems. Most saltwater fish tanks should have at least 10x the turnover rate of the aquarium’s total volume. For example, if you have a 75-gallon fish tank, you should have at least 750 gallons of water turning over every hour. Many saltwater fishkeepers believe that a higher turnover rate is better for the overall system. Your water’s flow rate should be changed based on the species of animal kept in the aquarium.

    A few outliers

    Certain corals, like SPS coral, enjoy faster-moving waters over leather corals. Seahorses and pipefish require slower-moving waters compared to tangs, clownfish, and others. I cannot list all the fish requirements in this article but before purchasing any animal, make sure that the setup you have is compatible with it. Saltwater-related mistakes are costly to your wallet and potentially the aquarium. You want to go into everything with an arsenal of information before making any moves.

    Sump Systems

    One of the most common filtration systems for larger saltwater (and a lot of freshwater) aquariums are sump system. To put it simply, a sump is a “fish tank” under a fish tank. They are usually set up in the aquarium stand. Sumps differ from fish tanks because they are usually set up or purchased with baffles. Baffles create separations often called chambers. Each chamber can hold different things such as protein skimmers, refugiums, and return pumps. There is a vast amount of things that can be done with sump systems to help keep your aquarium clean.

    One of the main benefits of sump systems is that you can put just about everything in it. They’re also excellent for saltwater aquariums because they add more water volume and increase oxygen exchange between the water and air. Furthermore, sumps are much easier to clean and it’s easier to remove/replace filter media when needed.

    Disadvantages of Sumps

    Even with all the advantages of sump systems, there are disadvantages. Sump systems overall, may cost you more money upfront. If you’re not a DIY type of person, purchasing an already plumbed sump will cost you some cash. You may need to plumb your aquarium and sump. You will also need to research and purchase a return pump that returns water into your aquarium at an appropriate rate. If your return pump is not strong enough, your sump can potentially overflow and flood your house. Also, purchase and/or build a sump that will not cause flooding when the power goes out. Water will siphon from your fish tank into the sump, so having a large enough sump should prevent any flooding.

    Quick Setup Information

    I am just skimming over the surface by setting up a saltwater aquarium with a sump. I would recommend doing more research on the topic. The easiest route to take is to purchase a drilled aquarium. Most drilled aquariums will come with a plumbing kit. Plumbing kits will provide you with the overflow piping and bulkheads. The only thing you’ll need to do is pipe the bulkhead down into the sump with PVC piping, choose the correctly sized return pump, and purchase/build a sump system. When plumbing, remember that elbows in piping can drastically slow down the flow. Also, make sure your piping is primed and sealed. This link will direct you to Amazon’s store page where you can purchase PVC cement.

    Final Notes

    There is a lot that goes into flow rates in every aquarium setup. It expands even more when you begin keeping unique animals such as coral and seahorses. Think about what you want to keep at home and plan your aquarium accordingly. Check out ATParium for more information on fish, invertebrates and more!