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Matala MDB — the diffuser platform that keeps fine-bubble discs level and out of the muck
A hollow polyethylene base you fill with sand or gravel, carrying one, two or four EPDM membrane discs. The I-slit membranes add under 6" of water-column back pressure — the lowest in the market per Matala — so a smaller air pump moves more air. Choose 9" discs or the higher-flow 12" discs.
- Platforms
- Single or double
- Discs
- 1, 2 or 4 × 9" / 12"
- Air flow
- 25–480 LPM
- Hose socket
- 3/8", 1/2", 5/8", 1"
- Weight
- Fill with gravel
Image coming soon
Mystic Koi’s take
The MDB11 on a Hakko 40 or 60 is the single most common aeration setup we sell for koi ponds. Go 12" discs if your pump has air to spare — the same base nearly doubles its airflow. Add the 3" riser pipe if the bottom is silty.
What it does
- Lowest back pressure< 6" water column added.
- Self-weighting baseFill with gravel; sits flat on soft bottoms.
- I-slit EPDM membranesOpen with air, seal when off; resist fouling.
- Quick uni-packLinks two platforms to one 3/4" outlet.
- 4-step hose socket3/8" to 1".
- Parts stockedDiscs, bases, fittings, risers.
MDB specifications (per Matala)
| Model | Platform : disc | Disc size | Air volume | Package | Ship wt |
|---|---|---|---|---|---|
| MDB11 | 1 : 1 | 9" | 25–120 LPM (0.9–4.2 CFM) | 12.2 × 5.5 × 10.6" | 3.3 lb |
| MDB11-12 | 1 : 1 | 12" | 80–200 LPM | — | — |
| MDB12 | 1 : 2 | 9" | 60–240 LPM (2.1–8.4 CFM) | 13 × 7.5 × 10.6" | 4.6 lb |
| MDB12-12 | 1 : 2 | 12" | 160–400 LPM | — | — |
| MDB22 | 2 : 2 | 9" | 60–240 LPM | 23.6 × 5.5 × 10.6" | 6.4 lb |
| MDB22-12 | 2 : 2 | 12" | 160–400 LPM | — | — |
| MDB24 | 2 : 4 | 9" | 120–480 LPM (4.2–16.8 CFM) | 23.6 × 7.6 × 10.6" | 9.5 lb |
| MDB24-12 | 2 : 4 | 12" | 320–800 LPM | — | — |
12"-disc air volumes are derived from the BHB-MD310 disc rating (80–200 LPM each).
Pairs well with
The science: why bottom aeration matters more than a waterfall
Oxygen enters water at the surface, and a diffuser’s rising bubble plume lifts bottom water up to the surface in a continuous loop. That circulation is the real work: it de-stratifies the pond, keeps the bottom from going anoxic, and carries ammonia to the filter. Fine bubbles transfer more oxygen per cubic foot of air because of their larger total surface area and slower rise. Warm water holds less oxygen (about 7.6 mg/L at 86 °F vs 11.3 mg/L at 50 °F), which is why summer nights are when koi gasp.
- Matala Water Technology Co. (2026). Aeration product data — Hakko linear pumps, MDB platforms, membrane diffusers, Ez-Air Pro kits. matala.com.tw.
- Boyd, C.E. (1998). Pond water aeration systems. Aquacultural Engineering 18(1): 9–40.
- USGS (2024). Dissolved oxygen solubility tables (fresh water, sea-level).
Questions we get about the MDB platform
Which pump for an MDB11?
Anything from an HK-25L to an HK-100L; the disc is happy from 25 to 120 LPM. For an MDB22 start at the HK-60L.
How deep can I place it?
To about 8 ft on a Hakko linear pump; deeper placements need the MPC rocking-piston compressor.
Matala at Mystic Koi
Matala filter media and pond equipment have been a koi-keeping staple for decades, and Mystic Koi has sold and run Matala gear in our own systems since we opened in Upland, California in 1996. Everything on this page ships from Matala USA (Sea Life Designs) or our ¾-acre facility. Not sure what fits your pond? Call or visit and we’ll size it with you.