Matt P
★★★★★
6 Sep 2026Purchased the retreat outdoor umbrella, had no isuues the quality is nothing but awesome would definitely recommend this product and my Acare was very easy to work with
Dam Aerators and Fountains
Two things decide what a dam needs: how wide it is, then how deep. Surface area sets the horsepower. Depth decides whether the unit floats on top or sits on the bottom. Everything else is what you want to look at.
Size it by surface area
Otterbine recommend 2 HP for every surface acre (about 0.4 hectares, or 4,000 m²) when the goal is water quality. Measure the water, not the paddock.
| Water surface | Start here | Minimum depth |
|---|---|---|
| Under 1,000 m² | Otterbine All-in-One 1/2 HP, or an Oase PondJet for display | 41 cm (50 cm for PondJet) |
| 1,000 to 2,000 m² | 1 HP aerating fountain | 75 cm |
| 2,000 to 4,000 m² (about an acre) | 2 HP aerating fountain | 75 cm |
| 4,000 to 6,000 m² | 3 HP aerating fountain | 75 cm |
| 6,000 m² to 1 hectare | 5 HP aerating fountain, or two smaller units spread out | 75 cm |
| Over 1 hectare | Several units, or a Giant Fountain where the display is the point | 1.2 m for a Giant |
Deeper than 2.4 metres? A fountain stirs the top of the water. It rarely reaches the floor of a deep dam, which is where the trouble starts. From about 2.4 m down, subsurface diffusers on the bottom move the whole water column, with every electrical part kept on the bank. Tell us the depth before you choose on looks.
Nothing in this range at the moment
We are between suppliers here. Tell us what you are after and we will let you know the day it lands, or point you at something that suits now.
Talk to usA dam is not a big pond. The water is deeper, the nutrient load comes off the paddock rather than from fish food, so the fix is oxygen and movement rather than filtration. Nothing on this page filters water. These units keep it moving so the dam can look after itself.
Otterbine build the floating units, in the United States, with a pattern wrapped around an aerating pump. Oase cover the smaller end with the PondJet floating fountain. Both come to Australia through Aquatec Equipment, so warranty work goes through us rather than an overseas office.
Which type suits your water
| Type | What you see | Suits depth | Water quality | Power |
|---|---|---|---|---|
| Aerating fountain, 1 to 5 HP | A full spray pattern | From 75 cm | Strong at the surface | Single phase to 3 HP, three phase at 5 HP |
| All-in-One, 1/2 HP | A small pattern, or none on mixer | From 41 cm | Good on small water | Single phase |
| Floating fountain (Oase PondJet) | Display up to 3.75 m high | From 50 cm | Surface only | Single phase |
| Subsurface diffusers | A patch of bubbles | 2.4 m and deeper | Treats the whole depth | Single phase, all on the bank |
| Aspirator or mixer | Nothing above the water | From 76 cm | Targeted circulation | Single or three phase |
| Giant Fountain, 10 to 25 HP | A landmark, up to 27 m | From 1.2 m | Display only, needs clean water | Three phase only |
Dam aeration questions, answered
What size aerator does my dam need?
Size it by surface area. Otterbine recommend 2 HP for every surface acre, about 0.4 hectares, when the aim is water quality. A one acre dam suits a 2 HP unit. Past a hectare, most sites run two units rather than one large one, because spreading the movement beats concentrating it.
Fountain or subsurface aeration?
Depth decides. A floating fountain moves the surface and gives you something to look at. From about 2.4 metres deep, diffusers on the bottom do far more for water quality, because they lift the stale water off the floor. Shallow dams suit fountains. Deep dams suit subsurface. Some sites run both.
Does it need an electrician?
Yes, every time. Units supplied in Australia run at 50 Hz, which means they arrive without the Otterbine Power Control Center. A licensed electrician supplies and installs the onshore isolator, RCD protection, the circuit breaker and any timer in a weatherproof enclosure, then runs cable in conduit to the water.
Can we still swim in the dam?
With subsurface aeration, yes: the compressor stays on the bank, so only air tubing goes in the water. Floating units have power in the water, so they are switched off before anyone swims.
How far from power can it sit?
Standard cable runs are 25 or 30 metres on the small units, with longer lengths quoted to order. Measure from the unit to the shore connection point, not to the house, then tell us the number.
Will it fix green water on its own?
It treats the cause that most dams share, which is low oxygen. It will not undo nutrient run-off from a paddock or a leaking septic. If something is feeding the algae, aeration helps but will not finish the job on its own.
Not sure where to start?
Tell us about your space and we'll suggest what suits.
