Penn-Plax Undergravel Aquarium Filter for 15-20 (high) Gallon Tanks – Two 11.2” x 11.25” Plates – Under Gravel System for Clear, Clean Water – Safe for Freshwater and Saltwater Tanks

Price: $32.99 - $22.99
(as of Nov 03, 2025 23:28:23 UTC – Details)

PENN-PLAX presents the Clear-Free Premium Under Gravel Aquarium Filter.
Those who’ve been around the aquatic block for a while
know that Under Gravel Filters (UGFs) are a testament of time.
This Filter is air driven and utilizes an Air Pump (not included) to cycle crystal clear water throughout your aquarium,
while keeping a crisp and neat look inside.
This means there’s less “moving parts,” making for simplistic and easy maintenance.
It’s suitable for most 15 – 20 (high) gallon aquariums, and is safe for Freshwater and Saltwater setups.Biological, Chemical, and Physical Filtration:
As air is pushed through the Air Stones and rises through the Lift Tubes,
water is gently suctioned through gravel and the filter plates,
allowing both air and water to pass through the Filt-a-Carb Activated Carbon Cartridges.
When water continues to be drawn through, anaerobic bacteria collects and colonizes within the gravel and filter plates.
Also Aerates Your Tank:
Since the Clear-Free Premium Under Gravel Filter is air driven
through the use of Air Stones and an Air Pump (not included), it also aerates your tank.
In essence, your aquarium is being filtered and aerated at the same time, though the same system!
It’s a filter and bubbler in 1!
Items Included:
The Clear-Free Premium Under Gravel Filter includes
2 Filter Plates
2 Adjustable Lift Tubes
2 Straight Airline Tubes
3 Filter Plate Connecters
2 Replaceable Filt-a-Carb Activated Carbon Media Cartridges
Measurements:
Each Filter Plate Separately = 11.25” (W) x 11.2” (D)
Filter Plates Together = 22.5” (W) x 11.2” (D)
Each Lift Tube at Filter Plate Base = 12” – 15”
Shop PENN-PLAX for All Your Pet’s Needs:
PENN-PLAX is a manufacturer and distributor of top quality pet supplies,
who specialize in creating excellent pet products for animals, both great and small.
Is Discontinued By Manufacturer ‏ : ‎ No
Product Dimensions ‏ : ‎ 22.5 x 11.2 x 16.25 inches; 1 Pounds
Item model number ‏ : ‎ CFU20
Date First Available ‏ : ‎ January 23, 2008
Manufacturer ‏ : ‎ Penn Plax, INC.
ASIN ‏ : ‎ B0002AQ1SI
Best Sellers Rank: #9,670 in Pet Supplies (See Top 100 in Pet Supplies) #64 in Aquarium Filter Accessories
Customer Reviews: 4.4 4.4 out of 5 stars 8,095 ratings 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); } }); });

NOTHING LIKE OLD SCHOOL: The Clear-Free Premium Under Gravel Filter is air driven and utilizes an Air Pump (not included) to cycle crystal clear water throughout your aquarium, while keeping a crisp and neat look inside. This means there’s less “moving parts,” making for simplistic and easy maintenance. This filter is suitable for most 15 – 20 (high) gallon aquariums.
BIOLOGICAL, CHEMICAL, AND PHYSICAL FILTRATION: As air is pushed through the Air Stones and rises through the Lift Tubes, water is gently suctioned through gravel and the filter plates, allowing both air and water to pass through the Filt-a-Carb Activated Carbon Cartridges. When water continues to be drawn through, anaerobic bacteria collects and colonizes within the gravel and filter plates.
ALSO AERATES YOUR TANK: Since the Clear-Free Premium Under Gravel Filter is air driven through the use of Air Stones and an Air Pump (not included), it also aerates your tank. In essence, your aquarium is being filtered and aerated at the same time, though the same system. It’s a filter and bubbler in 1.
ITEMS INCLUDED: The Clear-Free Premium Under Gravel Filter includes 2 Filter Plates, 2 Adjustable Lift Tubes, 2 Straight Airline Tubes, 3 Filter Plate Connecters, and 2 Replaceable Filt-a-Carb Activated Carbon Media Cartridges.
MEASUREMENTS: Each Filter Plate Separately = 11.25” (W) x 11.2” (D) / Filter Plates Together = 22.5” (W) x 11.2” (D) / Each Lift Tube at Filter Plate Base = 12” – 15”
COLOR MAY VARY: Please note: the plates that go on the bottom of your tank beneath a layer of gravel or other substrates may be Blue or Black.