Aquarium Filter Turnover & Flow Rate Calculator (L/h, GPH & Bio-Media)
Calculate the exact real filter flow rate (L/h or GPH), manufacturer box pump rating after -35% media/head-loss drag, and ceramic bio-media volume for shrimp, community, cichlid/discus, or marine reef aquariums.
Recommended Filtration & Bio-Media Specs
Target Real Net Flow
800 L/h – 1,200 L/h
Actual water circulated per hour (4–6x/h)
Required Filter Box Rating
1,231 L/h – 1,846 L/h
Manufacturer pump rating to buy (+54% buffer for -35% drag)
Recommended Bio-Media Volume
5 L (~3.8 kg)
Porous ceramic rings / sintered glass matrix
Test Your Current Filter Rated Flow (Optional)
Adjust slider to see if a specific filter model is Underfiltered, Optimal, or High Flow for your tank.
🟢 Optimal Filtration Turnover Achieved
Your tested pump sits right in the sweet spot—delivering complete ammonia/nitrite conversion and crystal-clear mechanical polishing.
Recommended Filters & Circulation Hardware for Your Tank
For tanks over 100 L (26+ gal) or heavy Cichlid/Discus bioloads, use a high-capacity UV canister filter with digital flow control:
Professional External Canister Filter Sunsun HW-3000 (LCD & UV)
Sponsored / Affiliate link
Sunsun HW-603B External Canister Filter
Sponsored / Affiliate link
Submersible Aquarium UV Sterilizer & Clarifier Pump
Sponsored / Affiliate link
7-in-1 Aquarium Water Test Strips (pH, NO2, NO3, GH, KH, Cl2)
Sponsored / Affiliate link
Frequently Asked Questions About Aquarium Filter Flow & Turnover
- How many times per hour should an aquarium filter turn over the water?
- Planted and nano shrimp tanks need 3–4x actual turnover per hour; tropical community tanks need 4–6x per hour; heavy-bioload Cichlid, Discus, and Goldfish tanks need 8–10x per hour; and Marine Reef tanks require 10–15x total hourly circulation.
- Why is a filter's real flow rate 35% lower than the L/h or GPH printed on the box?
- Manufacturers test pump flow with an empty filter canister at zero vertical lift height. Once you fill baskets with sponges, filter floss, and ceramic bio-rings and pump water up 1.2 meters of tubing into the aquarium, friction and head pressure reduce actual water flow by 30–40%.
- How much ceramic biological filter media do I need per 100 liters (26 gallons)?
- Allow 1.5–2.5 liters of porous ceramic rings or sintered glass matrix per 100 liters for standard community tanks, and 4.0–5.0 liters of bio-media per 100 liters for heavily stocked Cichlid, Discus, or Goldfish aquariums.