Blog

aquaponictec.com

<< All Blog

Electrical Control Box of RAS

In a Recirculating Aquaculture System (RAS), the biological filter (biofilter) is essential for converting toxic ammonia (from fish waste) into less harmful nitrate through the nitrogen cycle.

a0a031509c9cc01d849b2c56e35bc2e
367394605a1dc42a8d023ad84a9a9c8
21110af7dc51374ecfe56bf6d4931fb
21
23
333
792cdaf75c1286b955cde003e786688

    1. Role of a Biofilter in RAS

    The biofilter hosts beneficial bacteria that perform nitrification: Ammonia (NH₃/NH₄⁺) → Nitrosomonas bacteria → Nitrite (NO₂⁻) Nitrite (NO₂⁻) → Nitrobacter bacteria → Nitrate (NO₃⁻) (Nitrate is removed via water exchange or denitrification.) Without a biofilter, ammonia/nitrite buildup can kill fish rapidly.

    2. Types of Biofilters for RAS

    Biofilters are categorized by their media type and flow design:

    A. Submerged (Fixed-Bed) Biofilters

    Media: Plastic beads, ceramic rings, or porous gravel. How it works: Water flows through a submerged media bed where bacteria colonize. Best for: Small to medium RAS, low energy use. Pros: Simple, low cost. Fox example, Moving Bed Biofilm Reactor (MBBR) (plastic media in suspension) and Fluidized Sand Filter (fine sand media, high efficiency).

    B. Trickling (Drip) Filters

    Media: Plastic bio-balls, lava rock, or structured PVC sheets. How it works: Water trickles over media exposed to air (high oxygen transfer). Best for: High-load systems (e.g., trout, salmon RAS). Pros: Excellent aeration, low clogging.

    C. Fluidized Bed Biofilters

    Media: Fine sand or plastic microbeads. How it works: Water flows upward, fluidizing media for max bacteria contact. Best for: High-density systems (shrimp, tilapia). Pros: Extremely efficient, compact.

    D. Bead Filters (Combined Mechanical & Biofiltration)

    Media: Floating plastic beads. How it works: Traps solids while providing surface area for bacteria. Best for: Small RAS, backyard systems. Pros: Dual function (mechanical + bio).
Recent Posts

Ready to build your aquaponics system? Let’s talk.

Get A Quote
en_GBEnglish (UK)
arالعربية en_GBEnglish (UK)