We independently evaluate all of our recommendations. If you click on links we provide, we may receive compensation. The 6 Best Filters for Axolotl An exotic animal veterinarian helped us sort the best from the rest By Arricca SanSone Arricca SanSone Arricca is a writer with a wide range of expertise, but whether it's gardening or baking, she has always dogs by her side. Her writing has appeared in Good Housekeeping, Oprah Magazine, and on MarthaStewart.com. Learn more about The Spruce Pets' Editorial Process Updated on 08/25/25 Credit: The Spruce Pets / Amelia Manley Filters for your axolotl tank are necessary to keep your pet healthy by removing waste and providing good bacteria that break down harmful waste chemicals. Because axolotls absorb water and oxygen through their skin, they are especially sensitive to poor water quality, making the right filter essential to their health. “Axolotls produce waste in the form of ammonia that dissolves in the water,” said Laurie Hess, DVM, exotic animal veterinarian at Chewy. “As they suck water in while breathing and feeding, they are exposed to these toxic waste products. Filters mechanically remove large waste particles and provide good bacteria that break down ammonia into less harmful chemicals.” Not just any aquarium filter is appropriate for axolotls. Avoid in particular substrate filters—also known as under-gravel filters—which are installed inside the tank and often cover the entire bottom, beneath your substrate. Substrate filters pull water through the filter from below the substrate (typically sand or gravel) and return clean water to the top of the tank. However, this mechanism of filtration tends to disturb the material at the bottom of your tank, which can be dangerous for an axolotl. “This sort of filter is not recommended for axolotls because they are prone to eating small objects that can fit in their mouths, such as substrate particles like sand or gravel. Ingesting particles can block their gastrointestinal tracts and lead to life-threatening illnesses,” Dr. Hess told The Spruce Pets. Using criteria from Dr. Hess and a wide range of research sources, we found the best filter for your axolotl. Our favorite for small tanks is the Penn-Plax Cascade Aquarium Canister Filter, for its ease of assembly and use, while we recommend the Aqueon Quietflow Canister Filter for larger tanks, thanks to its easy setup and quiet operation. Top Picks Best Overall, Small Tank: Penn-Plax Cascade Aquarium Canister Filter 500 at Amazon $112 Jump to Review Best Overall, Large Tank: Aqueon Quietflow Canister Filter at Amazon $145 Jump to Review Best Budget Filter: Zoo Med Nano 30 External Canister Filter at Chewy $79 Jump to Review Best Sponge Filter: Pawfly Aquarium Sponge Filters at Amazon $7 Jump to Review Best Hang On The Back Filter: Hagen AquaClear Power Filter at Amazon $38 Jump to Review Another Great Budget Filter: MarineLand Power Filter at Amazon $43 Jump to Review Best Overall, Small Tank Penn-Plax Cascade Aquarium Canister Filter 500 Credit: Chewy $112 $101 at Amazon $135 at Wayfair View on Walmart What We Like Easy assembly Hassle-free maintenance Rotating valve taps make it easy to install in tight spaces Quiet operation What We Don't Like Can be tricky to prime This canister filter is used externally and offers mechanical, chemical and biological filtration. The two stackable trays, which come with coarse sponge and activated charcoal, are easy to access so you can customize filtration. This also makes maintenance a breeze because it’s not a hassle to disassemble and reassemble. The unit has a push button primer and two independent valve taps that rotate 360 degrees, which fits into tight spaces and helps prevent hose kinks. The base is fairly sturdy so it won’t tip over easily if accidentally bumped. It’s also one of the more quiet filters on the market, especially for the price point. There’s a slight hum from the motor, but it’s not overwhelming. Dimensions: 11.5 x 9 x 13.5 inches | Flow Rate: 115 gallons/minute | Appropriate for Tank Sizes: 30-gallon and under Best Overall, Large Tank Aqueon Quietflow Canister Filter Credit: Chewy $147 at Amazon $127 at Chewy What We Like Set up is easy Relatively quiet Additional layer of filtration What We Don't Like Water polishing cartridge must be replaced monthly This canister filter includes three filtration baskets with foam pads for mechanical filtration, carbon for chemical filtration, and bio-balls and bio-ceramic rings for biological filtration. It’s also fairly quiet. A water polishing basket with a replaceable carbon cartridge hangs on the back of the aquarium, which reduces how often the media baskets have to be replaced. This also provides one more layer of filtration before the water is put back into the tank. The Aqueon Quietflow is available in three sizes, making it useful in tanks ranging from 30 to 150 gallons Dimensions: 16.25 x 14.34 x 14 inches | Flow Rate: 200 gallons/minute | Appropriate for Tank Sizes: 40 to 55 gallons, 55 to 100 gallons, 100 to 150 gallons Best Budget Filter Zoo Med Nano 30 External Canister Filter Credit: Chewy $79 at Chewy What We Like Small footprint High flow rate for small tanks Rubber feet for stability What We Don't Like Doesn’t include filter media With a 160 GPH flow rate, the Zoo Med Nano External Canister Filter is appropriate for up to a 30-gallon tank. It’s also relatively quiet for such a reasonable price point. There’s a divider in the middle so you can use whatever medium you prefer. Even though it’s very small and lightweight, it is sturdy and resists tipping over when filled with media and water. Rubber feet on the bottom keep it from bouncing around or vibrating. Dimensions: 7.5 x 7.5 x 12.4 inches | Flow Rate: 160 gallons/minute | Tank Sizes: 30-gallon Best Sponge Filter Pawfly Aquarium Sponge Filters Credit: Amazon $7 at Amazon What We Like Cuts down on the operating costs of pump filters Quiet aeration Helps a keep the water crystal-clear What We Don't Like Meant to be used as a supplemental filtration option only Pawflys Aquarium Sponge Filters are a suitable add-on for a more robust pump filtration system. And, since Axolotls produce a lot of ammonia waste, the extra peace of mind is worth it for most. Use these sponges to lower the operating costs of your pump filter, while assuring crystal-clear water for your little pet salamander. When paired with an air pump, these sponge filters provide mechanical and biological filtration to trap debris, and quiet aeration, which causes no additional stress to your Axolotls. The manufacturer recommends removing and cleaning these sponges every two to four weeks (with aquarium water, only!) to achieve maximum efficiency. Dimensions: 1.5-inch diameter x 3 inches (3-gallon), 2-inch diameter x 4.8 inches (10-gallon), 2-inch diameter x 6.2 inches (20-gallon), 2-inch diameter x 6.3 inches (30-gallon), 3-inch diameter x 8.3 inches (50-gallon), 4.6-inch diameter x 8 inches (60-gallon) | Flow Rate: Not available | Tank Sizes: 3-gallon, 10-gallon, 20-gallon, 30-gallon, 50-gallon, 60-gallon Best Hang On The Back Filter Hagen AquaClear Power Filter Credit: Amazon $38 at Amazon What We Like Quick and easy installation Filters up to seven times more than larger comparable filters Two-year warranty from manufacturer What We Don't Like Impeller tends to get stuck (though it's easy to free) Hagen's AquaClear Hang-On Power Filter conveniently attaches to the back of a fish tank, offering mechanical, chemical, and biological filtration with little noise. It features activated carbon and AquaClear foam to assure superior water quality for your Axolotls. This filter is designed to prevent water by-pass around the filter, maximizing its efficiency while preserving the natural "good" bacteria that are beneficial for an Axolotl's tank. The AquaClear Power Filter is especially suitable for Axolotl tanks due to its formulated ammonia remover, exclusively designed for this particular filter. It's available in various sizes, which can filter up to 110-gallon tanks, and comes with a two-year unconditional guarantee. Dimensions: 4.5 x 7 x 6.5 inches (5- to 20-gallon), 4.5 x 8.2 x 6.7 inches (10- to 30-gallon), 9.37 x 8.03 x 4.33 inches (20- to 50-gallon), 11.5 x 9 x 6.5 inches (40- to 70-gallon), 17.4 x 12.5 x 11 inches (60- to 110-gallon) | Flow Rate: 100 gallons/hour (5- to 20-gallon), 150 gallon/hour, (10- to 30-gallon), 200 gallons/hour (20- to 50-gallon), 300 gallons/hour (40- to 70-gallon), 500 gallons/hour (60- to 110-gallon) | Tank Sizes: 5- to 20-gallon, 10- to 30-gallon, 20- to 50-gallon, 40- to 70-gallon, 60- to 110-gallon Another Great Budget Filter MarineLand Power Filter Credit: Amazon $43 at Amazon $47 at Chewy $85 $65 at Petco What We Like Effective fine particulate filtration Very easy setup Available in five tank size filters Fairly quiet operation What We Don't Like Rotating filter wheel more prone to clog The MarineLand Penguin Power Filter is another excellent budget-friendly pick that comes highly rated on Amazon, garnering over 15,200 five-star reviews. It features a three-stage filtration system, including a patented BIO-wheel that facilitates the growth of beneficial bacteria necessary for biological filtration. We should note that rotating filters are more challenging to keep clean and tend to clog more frequently. Nevertheless, we found this MarineLand filter quite effective at removing fine particulates. Additionally, many reviewers have commented on its quiet operation. Also, there are multiple tank size options available: 75 GPH, 100 GPH, 150 GPH, 200 GPH, and 350 GPH. Dimensions: 5.31 x 5 x 7.56 inches (up to 10-gallon); 5.5 x 5.5 x 8 inches (10- to 20-gallon); 8.25 x 6 x 7.38 inches (20- to 30-gallon); 9.4 x 6.3 x 7.5 inches (30- to 50-gallon); 15.25 x 6.12 x 8 inches (50- to 75-gallon) | Flow Rate: 75 gallons/hour (up to 10-gallon), 100 gallon/hour, (10- to 20-gallon), 150 gallons/hour (20- to 30-gallon), 200 gallons/hour (30- to 50-gallon), 350 gallons/hour (50- to 75-gallon) | Tank Sizes: up to 10-gallon, 10- to 20-gallon, 20- to 30-gallon, 30- to 50-gallon, 50- to 75-gallon Final Verdict Our top pick for small tanks is Penn-Plax Cascade Aquarium Canister Filter for its ease of assembly and use, while we like Aqueon Quietflow Canister Filter for larger tanks for its easy setup and quiet operation. What to Look For in Axolotl Filters Filter Types Canister filters sit outside the tank and are pressurized to pump water through the filter media. When sized appropriately for the tank, without a strong flow, these are excellent filters for an axolotl tank, says Dr. Hess.Chemical filters are usually integrated within a canister filter. The chemical part of the filter works in addition to the mechanical and biological filters by using activated carbon to absorb and pull toxins out of the water. When present in an appropriately sized canister filter, chemical filters work great for axolotls.Substrate filters, also known as an under-gravel filter, which sits inside the tank, pull water through the filter from below the substrate (typically sand or gravel) and output the water at the top of the tank. This type is not recommended for axolotls, says Dr. Hess. Sizing A filter must be properly sized to the volume of water in the tank, which should be a minimum tank size of 20 gallons. Tanks of 20 to 40 gallons are the typical range for axolotls. In general, axolotls are better housed alone, as they tend to chew on each other when housed together, says Dr. Hess. Water Flow The filter also should not produce a strong current from a high flow rate, which will stress the axolotl. “The flow should be gentle and not as strong as a stream or river,” says Dr. Hess. Gallons Per Hour Ideally, you want to have five water changes per hour for an axolotl tank. To ensure the flow rate isn’t too high for an axolotl, divide the flow rate by five to get the ideal tank size for an axolotl when using that filter. As long as the tank is close to that ideal size, the flow rate for the axolotl should not be too high. So, for a 20-gallon tank, you need a filter with a flow rate of about 100 GPH but not more than 150 GPH, says Dr. Hess. Why Trust The Spruce Pets? Writer Arricca SanSone researched the market based on criteria and recommendations from Laurie Hess, DVM, exotic animal veterinarian at Chewy and in private practice, as well as comparing product reviews. She has written extensively about nutrition and pet products for The Spruce Pets. Arricca’s has also taken deep dives into the best whisker fatigue bowls, puppy foods, dog ID tags, and even the best beekeeping suits. The 9 Best Small Fish Tanks of 2026 Explore more: What to Buy Aquarium Reviews