Dymax Slim Flo SF-240, Nano HOB Filter, Medium
SKU: DM-SF240
MSRP: $ 24.19
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Available Through Authorized Retailer
- The Dymax Slim Flo SF-240 is a hang-on-back filter built for freshwater planted tanks up to 8 gallons.
- It suits small nano tanks, shrimp setups, and beginner planted tanks in the 5- to 8-gallon range.
- It delivers up to 60 GPH of filtration through a wool carbon cartridge that traps waste and clears water.
- The adjustable flow dial lets you slow the output to a crawl, protecting delicate shrimp and fry.
Dymax
Dymax is a Singapore-based aquatic brand with over 23 years of expertise in designing and manufacturing aquariums, filters, aquatic foods, and other fishkeeping products.
HOB Filter for Small Planted Tanks and Shrimp Setups
The Dymax Slim Flo SF-240 Filter is a hang-on-back filter rated for freshwater aquariums from 5 to 8 gallons. It pulls water through a wool carbon cartridge that handles both mechanical filtration and basic chemical polishing in a single pass. For hobbyists who want clean, clear water in a small planted tank without the footprint or plumbing of a canister filter, the SF-240 is a practical starting point.
At 60 GPH with adjustable flow, the SF-240 turns over an 8-gallon tank more than seven times per hour at full output. Dial it back, and it runs gently enough for Neocaridina shrimp or slow-swimming community fish. The intake sponge prevents small inhabitants from being pulled into the unit, and the leveling knob ensures a secure hang on rimmed or lightly irregular tank edges.
Key Features:
- Hang-on-back design keeps the full tank interior clear for plants, hardscape, and livestock
- Adjustable flow dial covers the full range from gentle shrimp-safe output to maximum turnover
- Wool carbon cartridge captures particulates and polishes water clarity in a single stage
- Quiet motor operation suitable for bedroom and living room setups
- Leveling knob accommodates tank rims that are not perfectly level
- Intake sponge protects shrimp and small fish from being drawn into the intake
- Replacement cartridges are sold separately as a 2-pack (DM-SFC-L)
Ideal For:
- 5 to 8-gallon planted tanks with shrimp colonies or small community fish like ember tetras or pygmy corydoras
- Beginner freshwater hobbyists who want a reliable HOB filter without the cost or complexity of a canister setup
- Hobbyists running a shrimp breeding tank who need precise flow control to protect juveniles
Pro Tips:
- Match the flow rate to your stock, not your tank volume. A colony of red cherry shrimp will do better at 30 to 40 GPH than at the SF-240's full 60 GPH. Dial down until you see minimal surface ripple and shrimp moving freely across the substrate.
- Do not skip the break-in period. A new wool carbon cartridge can cloud the water slightly for the first 24 to 48 hours as carbon dust settles out. This is normal and clears on its own without a water change.
- Replace the cartridge before it clogs, not after. Check flow every three to four weeks. A slow drip back into the tank means the cartridge is full and flow has dropped, which reduces filtration efficiency before you notice it visually.
What's Included:
- Dymax Slim Flo SF-240 filter unit
- Intake tube
- Intake sponge
- Leveling knob
- Filter media (wool carbon cartridge)
- Power cord
Specifications:
- Model: SF-240
- SKU: DM-SF240
- Tank Size Rating: 5–8 gallons
- Max Flow Rate: 60 GPH
- Flow: Adjustable
- Filter Media: Wool carbon cartridge
- Replacement Cartridge SKU: DM-SFC-L (sold separately)
Instructions:
- Attach the intake sponge to the bottom of the intake tube.
- Hang the filter unit on the tank rim and use the leveling knob to achieve an even, stable fit.
- Fill the filter body with tank water before plugging in to prime the pump and prevent dry-start noise.
- Insert the wool carbon cartridge into the filter chamber.
- Plug into a standard outlet and set the flow dial to the lowest setting.
- Gradually increase flow as needed for your tank inhabitants.
- Replace the wool carbon cartridge every 3 to 4 weeks, or sooner if the flow noticeably drops.
Note: Do not run the filter dry. Always ensure the intake tube reaches below the waterline before powering on.