Description
xOverview
PENN-PLAX presents the Clear-Free Premium Under Gravel Filter, an air-driven system designed for most 20 (Long) to 29-gallon tanks. It relies on a separate air pump (not included) to push air through stones, cycling water through two filter plates and Filt-a-Carb carbon cartridges. The design emphasizes fewer moving parts for straightforward maintenance and a tidy interior appearance.
Filtration that covers Biological, Chemical, and Physical Needs
As air travels through the air stones and lifts through the tubes, water is gently drawn through gravel and the filter plates. It then passes through carbon media, supporting a multi-stage filtration process. In the process, beneficial bacteria can colonize within the gravel and on the plates, contributing to a balanced aquatic environment without making medical claims.
Aeration and Filtration — in One System
Because the unit is air-driven, it also aerates your water via air stones. The result is a combined filtration and bubbling effect that can help maintain oxygen levels, all within a single setup.
What’s Included and Size Details
The kit contains two filter plates, two adjustable lift tubes, two straight airline tubes, three filter plate connectors, and two replaceable Filt-a-Carb activated carbon cartridges. Each plate measures 14” W x 11.1” D; together they span 28” wide. Lift tubes span roughly 13”–16” from the plate base.
- Two 14” × 11.1” filter plates
- Two adjustable lift tubes
- Two straight airline tubes
- Three connectors for plates
- Two replaceable Filt-a-Carb carbon cartridges
Why This System Might Fit Your Aquarium
If you want a simple, low-maintenance under-gravel option that supports clear water in freshwater or saltwater setups, this Penn-Plax unit offers a compact, efficient approach. Color of the under-gravel plates may vary from the images, but the overall design remains focused on reliable filtration and gentle water movement.
Installation and Maintenance Tips
Pair with an appropriate air pump and stones, position the plates for even flow across the gravel, and keep lift tubes adjustable to control water movement without stirring substrate. Regularly inspect and replace carbon cartridges as needed, and check hoses for kinks during routine care.
FAQ
Q: What tanks is this undergravel filter compatible with?
A: Designed for most 20 (long) to 29 gallon aquariums, suitable for freshwater and saltwater setups.
Q: Does the setup require a separate air pump?
A: Yes. It is air-driven and uses an external air pump and stones to drive filtration and aeration.
Shipping & Return
xReturns Policy
You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Shipping
We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.
When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.
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