SOBO Hanging Filter (HOB) – External Waterfall Filter for Aquarium

🌊 Why a HOB Filter Outperforms Internal Filters

Internal sponge filters and powerheads keep mechanical and biological media submerged inside the tank, consuming display space, creating unsightly equipment and limiting the volume of media you can use. A Hang-On-Back (HOB) filter changes all of this — the entire filter body, motor and media chambers sit outside the aquarium, hanging on the rear rim.

The SOBO HOB filter draws water up through the intake tube, passes it through three separate filtration layers and returns it to the tank via a waterfall spillway. This waterfall action is not merely aesthetic — it creates continuous surface agitation that drives oxygen exchange, replenishing dissolved oxygen and releasing CO₂ at the water surface. Fish in well-oxygenated tanks are more active, eat better and show improved colouration.

The adjustable flow valve lets you dial output precisely — reduce flow for betta and gourami tanks that prefer calm water, open fully for goldfish and cichlid tanks that need strong circulation.

📋 Product Specifications

💰 All 5 Models at a Glance

✅ Three-Layer Filtration — How It Works

• Layer 1 — Mechanical (Coarse Sponge): First contact — traps fish waste, uneaten food and particulates. Rinse in aquarium water every 2–4 weeks. The most frequently serviced layer — easy to remove and replace.
• Layer 2 — Biological (Ceramic Bio-Rings / Bio-Balls): Provides surface area for beneficial nitrifying bacteria — converts ammonia to nitrite and nitrite to nitrate. Rinse gently every 1–2 months in aquarium water only. Never discard this media unless completely degraded.
• Layer 3 — Chemical (Activated Carbon): Final polish — removes dissolved organic compounds, yellow tannin discolouration and odour. Replace every 4–6 weeks. Skip carbon when dosing medications — reinsert after treatment is complete.

🐟 Recommended For

• Goldfish Tanks: Goldfish produce heavy waste and benefit from strong waterfall oxygenation — WP-408H or WP-508H recommended for 3+ goldfish.
• Community Tanks (Tetras, Barbs, Danios): Adjustable flow prevents strong current stress. WP-308H suits most 3 ft community setups perfectly.
• Betta Tanks: Use WP-628H at minimum flow — the waterfall return is gentle enough for bettas when set to the lowest flow setting.
• Turtle Tubs: Turtles produce exceptionally high organic waste — HOB filters with adjustable flow are the standard choice for turtle setups.
• Nano and Quarantine Tanks: WP-628H is ideal for 1–2 ft hospital or quarantine tanks — powerful enough to cycle but compact and gentle.

📦 What's in the Box