--- product_id: 52791899 title: "Penn-Plax Premium Under Gravel Filter System - for 40-55 Gallon Fish Tanks & Aquariums (CFU55" brand: "penn-plax" price: "ΰΈΏ5505" currency: THB in_stock: true reviews_count: 13 category: "Penn Plax" url: https://www.desertcart.co.th/products/52791899-penn-plax-premium-under-gravel-filter-system-for-40-55 store_origin: TH region: Thailand --- # Safe for fresh & saltwater Discreet undergravel design Fits 40-55 gallon tanks Penn-Plax Premium Under Gravel Filter System - for 40-55 Gallon Fish Tanks & Aquariums (CFU55 **Brand:** penn-plax **Price:** ΰΈΏ5505 **Availability:** βœ… In Stock ## Summary > 🌟 Elevate your aquarium game with invisible power filtration! ## Quick Answers - **What is this?** Penn-Plax Premium Under Gravel Filter System - for 40-55 Gallon Fish Tanks & Aquariums (CFU55 by penn-plax - **How much does it cost?** ΰΈΏ5505 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.th](https://www.desertcart.co.th/products/52791899-penn-plax-premium-under-gravel-filter-system-for-40-55) ## Best For - penn-plax enthusiasts ## Why This Product - Trusted penn-plax brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Seamless Integration:** Hidden undergravel plates keep your aquarium sleek and stylish without compromising filtration. - β€’ **Effortless Installation:** Comes with all essential components except air pump and tubing, making setup quick and hassle-free. - β€’ **Versatile Compatibility:** Engineered to perform flawlessly in both freshwater and saltwater environments, perfect for any aquatic setup. - β€’ **Proven Classic Efficiency:** Revive the trusted undergravel filtration method that’s stood the test of time for cleaner, healthier tanks. - β€’ **Optimized for Medium Tanks:** Specifically designed for 40-55 gallon aquariums, ensuring maximum filtration coverage and water clarity. ## Overview The Penn-Plax Premium Under Gravel Filter System is a reliable, easy-to-install filtration solution tailored for 40-55 gallon tanks. Its discreet design enhances aquarium aesthetics while providing effective filtration for both freshwater and saltwater environments. Trusted by enthusiasts for decades, this system includes all necessary parts except the air pump and tubing, making it a versatile and classic choice for maintaining crystal-clear aquatic habitats. ## Description Free delivery and returns on eligible orders. Buy Penn-Plax Premium Under Gravel Filter System - for 40-55 Gallon Fish Tanks & Aquariums (CFU55 at desertcart UK. Review: Old way is the best way! - Back in the 80`s & 90`s, i used to keep fish, but had a break from it till 3 years ago, when i purchased my current setup. Back then, pretty much the only filter system around, was undergravel filters and they always worked great. Nowadays though, with modern systems, undergravel filters sort of died out, or so i thought. I have an Ocellaris 1400UV canister on my tank, which i have to say, does an amazing job, but because i`ve now had the tank 3 years, i decided to do a complete clean out of the tank and i have to say, i was blown away by how much muck was in this tank, especially in the gravel. One of the biggest causes of it, was the volcanic substrate i`d put in the tank when it was first setup, as it worked it`s way through the gravel, it had literally turned into lumps of mud and then along with all the other muck, well, you can imagine. So, after coming across these undergravel filters and the fact you could still buy one, i decided to fit this one to my take, because lets face it, you can`t have enough filtering. It all went together great and the only thing i had to do, was trim about 20mm off the width, because it was slightly wider than the tank (front to back). The kit comes with everything you need, even the air stones, all you need to buy, is the pipework and the air-pump. So far, it`s working great, but it has only been a few days. I`ve uploaded a video to show it working. The tank looks a little yellow/orange, because at the time, my full spectrum light was going into sunset mode, but you can see what you need to :) Great kit, easy to fit and great value as well, certainly worth fitting. Review: Great system - Goes together easily, well made. Re starting an old tank with limited access, so this is ideal. ## Features - This undergravel filter hides from view for maximum aesthetics (color of plates may vary). Safe for use in both freshwater and saltwater tanks ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B003UTNOU6 | | Allergen Information | Cashews Free | | Batteries Included | No | | Batteries required | No | | Best Sellers Rank | 68,557 in Pet Supplies ( See Top 100 in Pet Supplies ) 325 in Aquarium Filters | | Colour | Blue or Black (color May Vary) | | Customer Reviews | 4.3 4.3 out of 5 stars (6,349) | | Date First Available | 13 Jun. 2013 | | Item Weight | 916 g | | Item model number | CFU55 | | Number of Items | 1 | | Pet Life Stage | All Life Stages | | Product Dimensions | 29.21 x 6.35 x 29.21 cm; 916.26 g | | Quantity | 1 | | Size | 40/55 | | Specific Uses | Indoor | ## Images ![Penn-Plax Premium Under Gravel Filter System - for 40-55 Gallon Fish Tanks & Aquariums (CFU55 - Image 1](https://m.media-amazon.com/images/I/819cRGofPsL.jpg) ## Available Options This product comes in different **Color, Size** options. ## Questions & Answers **Q: Hello! i have a 55 gallon tank. how does this filter work? does it come with everything i need? and if there is a video on it please send it. thanks** A: Thank you for your question. This filter has a plastic filter plate which lies under the gravel of the tank. This plate allows water to flow freely under the gravel. Water is drawn through the gravel and cleaned removing bateria and debris. In order for this air filter to work properly you will need an air pump as well as airline tubing. We like the Air Pod Pump B003DHYB52 and B0002563MW for air tubing. We don't have a video at this time but will have one soon. **Q: Can i configure this to fit a container that is 12.5" x 12.5"? Can experts recommend something better if not?** A: The 40/55 comes with four plates. Each plate has two tube attachments. One plate would fill a 12.5". Even if it were a little big you could score it (its plastic) and make it fit. **Q: Is it 11.5' square as in the decription or 13" as in the picture?** A: If you're getting it for a 55 gal aquarium the best I can tell you without tearing mine up out of my tank is that its perfect for the 55g , I've got them in my 10g , 39g bow front , 55g , and one in my 60g acrylic. **Q: What size should i get gor a 36 gallon tank** A: I have a 55 gallon tank and I used all the supplies flooring pieces, I think using this you may only require 3 of the flooring pieces possibly two if it’s a taller tank and not a show tank ## Customer Reviews ### ⭐⭐⭐⭐⭐ Old way is the best way! *by M***K on 1 November 2024* Back in the 80`s & 90`s, i used to keep fish, but had a break from it till 3 years ago, when i purchased my current setup. Back then, pretty much the only filter system around, was undergravel filters and they always worked great. Nowadays though, with modern systems, undergravel filters sort of died out, or so i thought. I have an Ocellaris 1400UV canister on my tank, which i have to say, does an amazing job, but because i`ve now had the tank 3 years, i decided to do a complete clean out of the tank and i have to say, i was blown away by how much muck was in this tank, especially in the gravel. One of the biggest causes of it, was the volcanic substrate i`d put in the tank when it was first setup, as it worked it`s way through the gravel, it had literally turned into lumps of mud and then along with all the other muck, well, you can imagine. So, after coming across these undergravel filters and the fact you could still buy one, i decided to fit this one to my take, because lets face it, you can`t have enough filtering. It all went together great and the only thing i had to do, was trim about 20mm off the width, because it was slightly wider than the tank (front to back). The kit comes with everything you need, even the air stones, all you need to buy, is the pipework and the air-pump. So far, it`s working great, but it has only been a few days. I`ve uploaded a video to show it working. The tank looks a little yellow/orange, because at the time, my full spectrum light was going into sunset mode, but you can see what you need to :) Great kit, easy to fit and great value as well, certainly worth fitting. ### ⭐⭐⭐⭐⭐ Great system *by S***F on 29 August 2025* Goes together easily, well made. Re starting an old tank with limited access, so this is ideal. ### ⭐⭐⭐⭐⭐ Old school works *by N***. on 6 May 2024* Some people say under gravel filters are no good but there is a reason they are still around. They work and they work well. If you don't mind paying exorbitantly high price's for replacement cartridges and media go ahead and by all the other types of filter media. The old school under gravel only needs an air pump. The filter itself has no moving parts that's why is was around so long. I have tried all the other types and decided to go back to this one. Easy to put together great quality made of durable plastic Great buy. And I probably will not need to replace it as there's no moving parts 😁 ## Frequently Bought Together - Penn-Plax Undergravel Aquarium Filter for 40-55 Gallon Tanks – Four 11.25” x 11.25” Plates – Under Gravel System for Clear, Clean Water – Safe for Freshwater and Saltwater Tanks (CFU55) - AQUANEAT Aquarium Air Pump 300GPH, for up to 200 Gallon Fish Tank, Powerful Hydroponic Aerator Pump with Tubing, Air Stones, Valves - Penn-Plax Standard Airline Tubing for Aquariums – Clear and Flexible – Resists Kinking – Safe for Freshwater and Saltwater Fish Tanks – 25 Feet --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.th/products/52791899-penn-plax-premium-under-gravel-filter-system-for-40-55](https://www.desertcart.co.th/products/52791899-penn-plax-premium-under-gravel-filter-system-for-40-55) --- *Product available on Desertcart Thailand* *Store origin: TH* *Last updated: 2026-04-27*