• Dymax Slim Flo SF-240, Nano HOB Filter, Medium
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Dymax

Dymax Slim Flo SF-240, Nano HOB Filter, Medium

Dymax Slim Flo SF-240, Nano HOB Filter, Medium

$26.99
$26.99
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Shipping calculated at checkout.

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.

Online exclusive: this item is ordered in for you and is usually ready within a few business days. Choose in-store pickup, local delivery or shipping at checkout.

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