UseCalcPro
Home
MathFinanceHealthConstructionAutoPetsGardenCraftsFood & BrewingToolsSportsMarineEducationTravel
Blog
  1. Home
  2. Pets

Aquarium Filter Size Calculator

Estimate real-world filter flow and media needs for freshwater, planted, reef, cichlid, and turtle tanks

Recommended Rated Flow

321 GPH

Turnover

5.0x/hr

Media

3.2 L

Use 0-1 ft for sponge filters, 3-5 ft for most canisters, and 1-2 ft for HOB filters.

Recommended Filter Rating

321

GPH minimum

Sizing Targets

Practical Range

321-369 GPH

Turnover

5.0x/hr

Media Volume

3.2 L

Filter Class

large

Maintenance Note

Plan to clean mechanical media roughly every 28 days and consider leaving headroom for dirty media and real-world flow loss.

PetcoAd
Petco

Everything your pet needs

Tanks, habitats, crates, litter & supplies — shop online or pick up in store

Free same-day delivery on orders $35+
Shop Petco
Trusted retailerSecure checkout

Affiliate link — we may earn a commission at no extra cost to you.

PetcoAd
Petco

Everything your pet needs

Tanks, habitats, crates, litter & supplies — shop online or pick up in store

Free same-day delivery on orders $35+
Shop Petco
Trusted retailerSecure checkout

Affiliate link — we may earn a commission at no extra cost to you.

What You'll Need

PONDFORSE Canister Filter, External Aquarium Filter Ultra-Quiet Water Circulation Cleaning Machine with Media for Fish Tanks and Aquariums

$55.994.1
View on Amazon
Marineland Bio-Wheel Penguin 200 GPH Power Aquarium Filter, Ultra-Quiet Hang-On-Back Fish Tank Filter with Multi-Stage Filtration for Aquariums Up to 40 Gallons

Marineland Bio-Wheel Penguin 200 GPH Power Aquarium Filter, Ultra-Quiet Hang-On-Back Fish Tank Filter with Multi-Stage Filtration for Aquariums Up to 40 Gallons

$36.894.3
View on Amazon
Fluval BioMax Biological Material Remover, 500 g - Biological Filter Media for Aquariums

Fluval BioMax Biological Material Remover, 500 g - Biological Filter Media for Aquariums

$19.054.8
View on Amazon

Aquatic Experts Classic Bonded Aquarium Filter Pad -12 Inches by 72 Inches by .75 Inch - Blue and White Aquarium Filter Media Roll Bulk Can Be Cut to Fit Most Filters, Made in USA

$22.494.7
View on Amazon

PONDFORSE Canister Filter, External Aquarium Filter Ultra-Quiet Water Circulation Cleaning Machine with Media for Fish Tanks and Aquariums

$55.994.1
View on Amazon
Marineland Bio-Wheel Penguin 200 GPH Power Aquarium Filter, Ultra-Quiet Hang-On-Back Fish Tank Filter with Multi-Stage Filtration for Aquariums Up to 40 Gallons

Marineland Bio-Wheel Penguin 200 GPH Power Aquarium Filter, Ultra-Quiet Hang-On-Back Fish Tank Filter with Multi-Stage Filtration for Aquariums Up to 40 Gallons

$36.894.3
View on Amazon
Fluval BioMax Biological Material Remover, 500 g - Biological Filter Media for Aquariums

Fluval BioMax Biological Material Remover, 500 g - Biological Filter Media for Aquariums

$19.054.8
View on Amazon

Aquatic Experts Classic Bonded Aquarium Filter Pad -12 Inches by 72 Inches by .75 Inch - Blue and White Aquarium Filter Media Roll Bulk Can Be Cut to Fit Most Filters, Made in USA

$22.494.7
View on Amazon

As an Amazon Associate, we earn from qualifying purchases.

Price as of Jun 27, 2026. Product prices and availability are accurate as of the date indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.

Related calculators

How much water should I change?Per-change volume, frequency and monthly water total, tuned to your tank type and source water.How much CO2 for a planted tank?Target CO2 bubble rate, pH drop and drop-checker color for a healthy planted aquarium.How many fish can it hold?Maximum stocking in total inches of fish for your tank size, with the filter GPH to support it.Aquarium CalculatorCalculate tank volume and glass dimensionsBetta Fish Tank CalculatorCalculate betta fish tank setup: heater wattage, filter size, water change schedule, and plant count. Get recommendations by tank size and room temperature.Axolotl Tank CalculatorCalculate axolotl tank volume, chiller size, and filter requirements. Get setup recommendations by axolotl count and room temperature for healthy care.

Example Calculations

140 gallon planted tank

Inputs

Tank Volume40 gallons
Tank TypePlanted
StockingModerate
Filter StyleCanister

Result

Recommended Ratingabout 300 GPH
Turnoveraround 6x per hour
Media Volumeabout 3.2 liters

This gives a planted tank enough circulation and media capacity without sizing the filter too tightly.

275 gallon cichlid tank

Inputs

Tank Volume75 gallons
Tank TypeCichlid
StockingHeavy
Filter StyleCanister

Result

Recommended Ratingabout 600 GPH
Turnoveraround 8x per hour
Media Volumeabout 6 liters

Cichlids produce heavy waste so a higher turnover rate and more biological media are recommended.

Frequently Asked Questions

Q

How much filter flow does an aquarium need?

Many freshwater tanks work around 5 to 6 times turnover per hour, while cichlid, reef, and turtle setups often need much more because of higher waste load and stronger circulation targets.

  • Community freshwater tanks often start near 5x turnover
  • Reef and turtle tanks commonly need substantially higher flow
  • Heavy stocking usually pushes the target above the basic rule of thumb
Q

Why is rated GPH higher than target turnover GPH?

Manufacturer ratings are usually measured with a clean filter and little or no head loss. Real flow drops once media gets dirty and the pump has to push water upward.

  • Canister filters lose flow through hoses and media
  • Dirty sponges and cartridges reduce real turnover further
  • Sizing with headroom is safer than matching the label exactly
Q

What filter type is best for a planted aquarium?

Canister filters are the most popular choice for planted tanks because they provide high flow with minimal surface agitation, which helps retain dissolved CO2 for plant growth.

  • Canister filters offer the most media volume per dollar for biological filtration
  • HOB filters create more surface agitation, which can drive off CO2
  • Sponge filters work well for small shrimp tanks but limit flow in larger setups
Q

How often should aquarium filter media be cleaned?

Mechanical media like sponges and floss should be rinsed in old tank water every 2 to 4 weeks. Biological media like ceramic rings and bio-balls should be rinsed only when flow drops noticeably.

  • Never rinse biological media in tap water, chlorine kills beneficial bacteria
  • Replace chemical media like carbon every 3 to 4 weeks
  • A flow rate drop of 30% or more usually means it is time to clean mechanical media

Related Resources

How to Size a Bilge Pump for a 25-Foot Boat (2026 GPH Guide)

Read our guide

Safe Reach Ladder Guide: What Height Do You Need? (2026)

Read our guide

Estate Cleanout Pricing (2026): Costs Plus Cash-for-Cars Removal

Read our guide

Aquarium Calculator

Aquarium Water Change Calculator

More Aquarium & Pet Calculators

Explore aquarium, reptile, feeding, and enclosure planning tools.

View Pet Calculators

Last Updated: Jul 13, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

UseCalcPro
FinanceHealthMathPrivacyTerms

© 2026 UseCalcPro