Undergravel Filter System for 20 Gallon Fish Tank, Air-Driven Biofiltration Aquarium Filter Kit with 20 Modular Plates & 2 Adjustable Lift Tubes, Cut-to-Fit Under Gravel for Clear Water

Product description

Designed for Flexibility & Easy Installation

Telescopic Lift Tube

Adjustable height fits most standard tanks. Ensures optimal water flow.

Interlocking Modular Design

Interlocking plates connect tightly for a secure, custom base layout.

Trimmable to Fit

Trim plates with standard scissors to fit around decor or irregular shapes.

Complete Accessory Kit

Includes all necessary fittings. Just add an air pump (sold separately) to start.

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Add to Cart

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Customer Reviews

3.9 out of 5 stars 81

3.9 out of 5 stars 81

3.9 out of 5 stars 81

Price

$9.98$9.98 $14.98$14.98 $19.98$19.98

Filter Plate Dimensions
8.26*11.02″ 11.02*16.53″ 13.78*22.04″

Fits Tank Size
5 Gallon Tanks 10 Gallon Tanks 20 Gallon Tanks

Recommended Air Pump
2-4 W 4-6 W 6-10 W

Package Dimensions ‏ : ‎ 11.65 x 6.97 x 3.15 inches; 1.21 Pounds
Item model number ‏ : ‎ BZ1030
Date First Available ‏ : ‎ December 16, 2025
Manufacturer ‏ : ‎ BaoZqua
ASIN ‏ : ‎ B0FYDJNKF6
Best Sellers Rank: #29,950 in Pet Supplies (See Top 100 in Pet Supplies) #304 in Aquarium Filter Accessories
Customer Reviews: 3.9 3.9 out of 5 stars (81) var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
Complete Filter Kit: Includes 20 interlocking filter plates, 2 adjustable lift tube set (with fitting), 2 check valve, 2 regulator, 2 extra air stone, 2 x 39″ extra airline tubing, 1 airline tee connector, and all required connectors—everything to build your undergravel system. (Please note: air pump and tank are not included and must be prepared separately.)
Efficient Undergravel Filtration: An external air pump (not included) supplies continuous airflow that drives water circulation, pulling water downward through the substrate and filter plates to trap debris and fines—delivering clear, clean water and steady flow in fish tanks.
Biofiltration & Aeration: Beneficial nitrifying microbes colonize the gravel bed and plate surfaces to break down ammonia and nitrite. Air-driven flow oxygenates the water column, supporting active fish behavior and a stable biological cycle for a cleaner, balanced tank.
Modular Plate Design: Includes 20 snap-fit undergravel plates (coverage up to 22.04″ x 13.78″). Fine 0.06″ mesh helps keep sand/gravel from fall-through; sturdy base helps resist bottom cracks and holds heavy substrate, improving water circulation and biofiltration in freshwater or saltwater tanks.
Easy Installation: Tool-free setup—lay plates, add substrate, attach the lift tube, and connect to an air pump (not included). The lift tube is adjustable and DIY cut-to-fit; use the included check valve to help stop backflow, and for 20 gal aquariums we recommend a quiet 6–10W air pump for optimal flow.