Air Pumps – are they just another thing to buy?

Air pumps in ponds – do you really need one? What purpose do they serve? In fish tanks, air pumps have become more a visual feature than a required piece of kit, blowing nice bubbles, which although obviously helps in the tank, most modern internal or external filters would cope perfectly well without.

So does this go for ponds too? No is the answer. Air pumps can make a dramatic difference to your pond, in both the clarity and quality of the water, as well as providing that all important oxygen and movement at peak times of the year, and better yet, if the unthinkable were to happen – your filter pump were to fail. In that situation, your air pump might just save the day – and the fishy inhabitants of your pond.

The key feature of air pumps – providing air. This essential thing may seem obvious, but in the height of summer, your pond will likely be depleted of oxygen, so this extra air will be a real help to the fish inside. During summer, you tend to find that algae goes a little mental, and in doing so it very helpfully spends its day producing oxygen into the pond – great. But at night, plants, algae included, use up oxygen. So if you have a particularly intense case of greenery growing, the fish will be fighting against this each night. Combine that with higher summer temperatures effecting, in that there is less dissolved oxygen in water the higher the temperature of it, and you’ll find that this can quickly become crippling. Certainly, getting rid of the algae will help massively, but ensuring there is an air pump anyway, just in case, seems logical.

Air pumps evidently provide air for the pond, that’s a given. But in doing so, they also create a water movement which first and foremost means that you won’t have a stagnant pond. Stagnant water is a breeding ground for bacteria, and if the water surface isn’t moving, oxygen isn’t getting into the water underneath. In stagnant pools there often develops a greasy film across the top of the water, which prevents any good air supply getting in. This will mean certain death for your fish, as well as any other amphibian life that may have taken up residence. Most people won’t be too worried about this – your filter pump provides water movement, so this doesn’t affect you. However, if that pump were to fail – have an electrical problem, get blocked, or just outright die, how would the pond cope then? A trip to buy another (or, obviously, order from Swell UK…) could take a day or two, and in the height of summer, this may not be an option. An air pump running alongside will cope with the pond without the filter pump for a week or so without too many issues (fish stocking dependent), giving you the time to get the filter pump fixed or replaced.

Another key benefit for air pumps also stems from the movement they create, as if this is well placed, it can create vortexes in areas of the pond further from the filter pump itself, areas that may not have such a great flow, and because of that, tend to get detritus building up on the bottom, as the weight of the muck and dirt are too heavy for the meagre flow. Placing air stones at the edges, or at the opposite end in elliptical ponds for example, can create that much needed flow, collecting the debris and moving it into a strong path of the filter pump, ensuring its collected and dealt with, so your pond will be cleaner and clearer for it. It may take a little practice to check air stones are placed in the right area – some may have a better effect than others, but even small round air stones, such as Jap Stones, will make a big difference when situated correctly.

If you find that the air pump you have is not as powerful as expected, or perhaps it’s an old one from a smaller pond, it can still be useful. Placing air stones mid-level in the pond will cause them to be more efficient, so even a small flow will be making a big difference.

In short – why not have one? For the benefits they add even at a normal level, they’re well worth the money. For the extra security if the worst should happen, they really are essential. Why not just have a little look at them.

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Fran is OATA certified and has been keeping and working with fish for more than 10 years. She has multiple tanks, including Marine fish-only and reef systems. Her main passion is in keeping nano systems, both freshwater and marines, and overcoming the challenges they bring.


  • Avatar Margaret Posted 06/08/2018 at 1:28 pm | Permalink | Reply

    My query is would you advise a much larger air pump to deal with a thick layer of pond sludge?
    My water filter pump is being blocked by it and its been raised as high as it can go to keep it off the layer of sludge.
    Its not a massive pond in a squeezed figure 8.
    Narrow end is 142cm across.
    Wide end 244cm
    Length is just over 3 m.

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