UNDER GRAVEL FILTER ( UFG )

A UGF (Undergravel Filter) is a filtration system for aquariums that uses a layer of gravel as a biological filter medium. It pulls water down through the gravel, trapping particles and encouraging beneficial bacteria growth, which helps break down fish waste and other organic material. Here’s a breakdown of how it works, its benefits, and some key considerations.

How an Undergravel Filter Works

1. Setup: The UGF consists of a perforated plate placed under the gravel layer in the aquarium.
2. Filtration Process: Water is drawn down through the gravel (acting as the filter media) and through the plate, either by an air-driven lift tube or a powerhead that creates suction.
3. Biological Filtration: The gravel bed provides surface area for beneficial bacteria, which convert harmful ammonia and nitrite from fish waste into less harmful nitrate (biological filtration).
4. Optional Mechanical Filtration: Although primarily a biological filter, some systems may also trap larger particles within the gravel, offering some mechanical filtration.

Advantages of UGF

• Effective Biological Filtration: Supports high levels of beneficial bacteria for a stable nitrogen cycle.
• Affordable: UGF systems are generally more budget-friendly than other filtration systems.
• Low Maintenance: With proper upkeep, UGFs can work effectively with minimal adjustments.
• Ideal for Smaller Tanks: UGFs are particularly useful for smaller tanks (up to 30 gallons) with light bioloads.

Disadvantages and Considerations

• Regular Cleaning Needed: The gravel can trap a lot of waste, leading to a buildup of detritus. Frequent gravel vacuuming is essential.
• Limited Mechanical Filtration: UGFs aren’t effective at removing fine debris, so they may require supplementation with a power filter or sponge filter for thorough mechanical filtration.
• Plants: Plant roots can become entangled in the filter plate, and the filter may reduce the available nutrients in the gravel.
• Compatibility with Sand: UGFs are less effective with sand substrates, as fine sand particles can clog the filter plate.

Maintenance Tips

• Gravel Vacuuming: Regular gravel vacuuming is critical to prevent waste buildup.
• Check Air Stones or Powerheads: Ensure lift tubes, airstones, or powerheads are functioning properly to maintain efficient water movement.
• Avoid Overfeeding: Excess food can quickly accumulate in the gravel, overwhelming the filter.

Summary

While UGF systems are effective for biological filtration, especially in small tanks, they require regular maintenance and may not suit tanks with fine substrates or heavy bioloads. When combined with additional filtration (like a hang-on-back or sponge filter), UGFs can provide an affordable, balanced filtration solution.