Can You Have Too Much of a Good Thing When It Comes to Aquarium Filtration?

Date Posted:14 August 2023 


What does fish tank maintenance have in common with Instagram? For the best look, you need to add a filter! Jokes aside, filters are a key part of any aquarium. But the question is, is it okay to have two or more filters in one tank? In this blog post, we’re going to discuss redundant filtration and why it may not be as redundant as the name implies. We’ll also discuss its limitations and when just one filter may suffice.


Can a Fish Tank Have Too Many Filters?


Before we dive into this question, let’s first clarify the meaning of ‘redundant filtration’ to ensure this discussion is as clear as a healthy tank. Quite simply, redundant filtration is when you use two or more filters in the one tank. Despite the name, redundant filtration is a common and recommended practice. By placing two or more filters in one fish tank, you’re setting your fish up for a cleaner experience in a way that won’t disturb their ecosystem. Aside from that, a second filter can make for a great backup should one fail or require replacement.


Can a fish tank have too many filters, though? While using multiple forms of fish tank filtration is often considered to be a good thing, there are still exceptions to the rule. Redundant filtration may not be the best idea if:


  • You’re managing a small tank.
  • You’re housing fish or aquatic creatures that struggle against excessive water flow.
  • Your tank hosts a high volume of plants.


It should be noted that in all of the above cases, redundant filtration is not the issue so much as excessive water flow. Sometimes, if the water flow is too strong, it can upset the natural balance of your ecosystem, stunting plant growth and potentially stressing your fish. If your tank is filtering water at a higher speed than your critters or plant life can handle, this can sometimes be a case of finding a second filter that works better for your tank. That said, you should review your situation and choose the option that best fits your circumstances. To facilitate optimal plant growth, for example, you need readily available CO2 that’s accessible via the water’s surface.


If your tank is an underwater jungle of sorts, a second filter—or increased water flow—may usher this CO2 away before the plants have had a chance to absorb it. Ultimately, you should not accept the recommendation of redundant filtration at face value, but instead consider all facets of the underwater wonderland contained to your tank. Generally speaking, though, redundant filtration is the more economical and effective setup for your fish and yourself.


What to Know When Choosing Your Fish Tank Filter System?


Is a Bigger Fish Tank Filter Better?


It’s true that bigger fish tanks often benefit more from redundant filtration. This goes double if you’re housing larger or more predatory fish. That said, bigger is not always better. What’s best is finding the aquarium cleaner that best fits your setup, be that a power, undergravel or canister filter. Whichever type(s) you select, remember that the corresponding aquarium size is just one part of the picture. Redundant filtration usually suits bigger aquariums, but it’s also not a one-size-fits-all solution.


Could My Filter Be Killing My Fish?


Of all the reasons to heed caution, this concern is principal. Unfortunately, redundant filtration or even an unsuitable fish tank cleaner can harm your fish. Sometimes, this is a case of the filters overperforming, upsetting the delicate balance of the fishes’ environment or initiating too strong a current. Other times, this is a case of the filters either underperforming or malfunctioning, resulting in poor-quality or contaminated water that could promote sickness or death. As you’re likely gathering, fish tank maintenance and filtration is a delicate balancing act. In any case, if you’re noticing your fish struggling against the default water flow, discoloured water or a decline in water quality, you’ll need to change up your setup pronto.


Need Further Clarification on Aquarium Filtration?


Aquarium filtration is one part of fish tank maintenance that’s incredibly complex. Aside from the movement from the power, undergravel, or canister filter itself, there are many moving parts to this process, including tank size, filter type(s), and how this all works together to create an environment for your plants and critters. If you’re having trouble navigating all the ins and outs of fish tank filtration, we’re here to help. Drop a line at Aquarium Kingdom today and we’ll help you piece it all together!