Aqua Pumps

Category: Ponds

  • Getting Clear Pond Water: A Practical Guide to Controlling Algae

    Getting Clear Pond Water: A Practical Guide to Controlling Algae

    A pond that has gone pea green is not dirty and it is not diseased. It is fertile. Algae are plants, and like every plant in the yard they grow when handed light and nutrients. Hit them with a bottle of something and you remove the algae without touching either of the two things that grew it, which is why the green is back a fortnight later. The fix that lasts is layered, it is mostly boring, and it takes a season to properly settle in.

    First, work out which green you have

    The two common problems look nothing alike once you know what you are looking at, and they need completely different treatment.

    • Green water: the water itself is cloudy green, like paint, and you lose sight of your hand a couple of hundred millimetres down. That is billions of single celled algae floating in suspension, and a UV clarifier deals with it.
    • Blanketweed or string algae: the water is clear but long green hair grows off the rocks, the waterfall lip and the pump housing. UV does close to nothing here: it is a nutrient and surface problem, and you pull it out by hand.

    Plenty of ponds have both at once, especially in the first warm month after a build. Work out which one is bothering you before you spend money.

    Where the nutrients are coming from

    Every algae problem traces back to a nutrient source, and in a backyard pond the list of candidates is short.

    • Overfeeding: uneaten fish food breaks down into exactly the nitrogen and phosphorus algae want. If food is still sitting on the bottom five minutes after you fed, you fed too much.
    • Too many fish for the volume: fish waste is fertiliser. A pond that coped with four fish is a different pond with fourteen, and our koi and fish pond basics guide covers stocking it sensibly.
    • Leaves and clippings: organic matter rotting on the bottom feeds the pond quietly, all year round.
    • Garden runoff: a pond sitting at the low point of a fertilised lawn collects everything that washes off after rain.
    • Full sun all day: light is the other half of the equation, and an unshaded pond through an Australian summer gets a great deal of it.

    The fix, in the order worth doing it

    1. Cut the inputs. Feed less, net the leaves out before they sink, and keep clippings and fertiliser away from the water. It costs nothing and it does more than anything else on this list.
    2. Get plants in. Aim for floating leaves covering something like half to two thirds of the surface: waterlilies out in the open water, marginals on the planting shelf. They shade the pond and they compete with algae for the same nutrients. Easily the most underrated step.
    3. Keep the water moving. Still water stratifies and warms, and warm still water is where algae does its best work. A pump turning the pond over properly also keeps the filter fed. If you are not sure yours is up to it, work through our pond pump sizing guide.
    4. Give the biology somewhere to live. A biological filter with enough media takes ammonia through to nitrate and houses the bacteria that take up nutrients instead of the algae. A new filter matures in weeks rather than days, slower again in cool weather, so do not judge it after a fortnight.
    5. Add a UV clarifier last, and only for green water. It clumps the suspended algae so the filter can strip them out. Sized and plumbed correctly it usually clears a green pond inside a couple of weeks. It is a finisher, not a cure, and our pond filtration and UV clarifier guide covers the sizing.

    Things that feel productive but set you back

    • Draining and refilling: you flush the mature bacteria out along with the algae and hand the pond a sterile, nutrient rich fresh start. The green usually comes back worse.
    • Scrubbing every surface at once: the same mistake on a smaller scale. Clean one part of the system at a time and leave the rest alone.
    • Rinsing filter media under the tap: chlorinated mains water kills the bacteria you spent weeks growing. Rinse media in a bucket of pond water instead.
    • Reaching for an algaecide in a fish pond: some are not safe for fish, and even the ones that are leave a mass of dead algae to rot, which pulls the oxygen down overnight and feeds the next bloom. Read the label properly and treat it as a last resort.

    Top-up water matters more than people expect

    Evaporation over summer means most ponds get topped up regularly, and what goes in matters. Mains supply is chlorinated or chloraminated, so dosing a pond straight off the hose knocks your filter bacteria about. Add it slowly, or use a dechlorinator if you are putting in a decent volume at once. Rainwater off the tank is gentler on the biology. Either way, top up little and often rather than in one big hit.

    The bit that needs a licensed hand

    Pumps and UV units are electrical gear living in a wet corner of the yard. Plugging an appliance into an existing weatherproof outdoor socket is yours to do. Installing a new outdoor power point, running a cable or hard wiring anything is licensed electrician work in every Australian state and territory, and each has its own electrical safety regulator setting those rules. Residual current device protection on outdoor circuits exists for a reason around water, so do not improvise with indoor leads and a wrap of tape.

    Give it a season

    New ponds go green. Established ponds go green again in spring, when the water warms before the plants wake up. Both settle on their own if the fundamentals are right. The people with permanently clear water are not the ones who bought the biggest UV unit. They are the ones who feed lightly, plant heavily and keep the leaves out.

  • Solar-Powered Pumps for Ponds and Fountains: What They Can and Can’t Do

    Solar-Powered Pumps for Ponds and Fountains: What They Can and Can’t Do

    A solar pump will happily run a small fountain, a birdbath bubbler or a garden spitter on a sunny day, and it will do it without a cord, a trench or a power bill. What it will not do is reliably keep a filtered fish pond turning over around the clock, unless you add a battery and accept that you are building a small off-grid power system rather than buying a pump. That is the honest line, and most of the disappointment people have with solar pumps comes from buying on one side of it and expecting the other.

    Direct drive versus battery buffered

    Every solar pump kit on the shelf is one of two things, and the difference matters far more than the badge on the box.

    • Direct drive: the panel wires straight to the pump, so the pump runs when the sun is on the panel and stops when it is not. A cloud goes over and the fountain drops off. The sun swings behind the house at four in the afternoon and it stops for the day.
    • Battery buffered: the panel charges a small battery through a controller, and the pump draws from the battery. You get run time through passing cloud, into the evening, and on a grey day, though the battery only gives you what the panel managed to put in.

    Direct drive kits are cheaper and simpler, and fine for pure decoration. If you want the water moving at a predictable time, or at all overnight, you want the battery.

    Where solar genuinely earns its keep

    The best case for solar is a feature sitting somewhere awkward: a pond down the back of a long block, a bubbler in a front garden with no outdoor outlet nearby, a small cascade on a rural property where the nearest power is a long way off. Running mains out to those spots means trenching, conduit and a sparky, and a solar kit sidesteps all of it.

    It also suits anything ornamental where an intermittent run is fine. Nobody minds a birdbath fountain going quiet after sunset, and wildlife ponds are a good fit too, because surface movement through the day discourages mosquitoes and puts oxygen in the water while the still night is closer to what a natural pond does anyway.

    Where it falls over

    Filtration is the big one. A filtered pond, and especially one with fish, wants its whole volume moving through the filter continuously, because the bacteria doing the biological work need a constant supply of oxygenated water. Cut the flow for a long stretch and that colony starts dying back, so when the sun returns your filter is doing less than you think. If you are running fish, get the turnover right first and treat solar as an extra, not the main pump. Our guide to sizing a pond pump to flow and head walks through what the pump actually has to move.

    Head height is the second trap. Solar pumps are generally modest performers, and lifting water up a waterfall or a tall feature eats the available flow quickly. A pump that looks impressive splashing away at ground level can arrive at the top of a metre of stacked rock as a dribble. Read the pump’s own performance curve at the height you are actually lifting to, and ignore the headline flow figure on the packaging, because that number is measured at zero lift.

    Season is the third. Winter sun sits lower and the days are shorter, so a panel that carried the feature comfortably in January can leave it stuttering in June. If the feature matters to you year round, size for your worst month, not your best.

    Panel siting is half the job

    People agonise over the pump and then drop the panel wherever it happens to fit, which is backwards. A good pump on a badly placed panel performs worse than a modest pump on a well placed one.

    In Australia the panel wants to face north, tilted up rather than lying flat, and it wants to be clear of shade for the middle of the day. Watch the spot across a full day before you mount anything, because the shade line from a fence, a pergola or a neighbour’s gum moves a long way between morning and afternoon. Give yourself enough cable to move the panel later, and wipe the dust off every few weeks. A dusty panel quietly loses you output and you will blame the pump.

    The electrical side, briefly

    A self contained low voltage kit, panel to controller to pump, is something you can install yourself. The moment you want a mains powered pump in the garden instead, or an outdoor outlet to plug one into, that is licensed electrical work in Australia and it belongs to a licensed electrician. Requirements and licensing are set by the electrical safety regulator in your state or territory, so check with them rather than taking a shop assistant’s word for it. Water, soil and mains voltage is not the place to save a few dollars.

    Keeping it running

    Solar pumps are usually small submersibles with tight clearances, which means they clog faster than a full sized pond pump and they do not enjoy running dry. Rinse the intake screen regularly, keep the water level up in summer when evaporation is quick, and clean the impeller if the flow drops off before you assume the panel is at fault. In cooler months, the same care that applies to any pond pump over winter applies here as well.

    Buy solar for what it is good at, moving water where power is inconvenient and the feature can afford to go quiet, and it will do that job for years. Ask it to be life support for a stocked pond and it will let you down on the first cloudy week. If you are still working out what your setup needs, start with our guide to water in the Australian garden.

  • Sizing a Pond Pump: Matching Flow to Pond Volume and Waterfall Height

    Sizing a Pond Pump: Matching Flow to Pond Volume and Waterfall Height

    Two numbers decide which pond pump you buy: how much water the pond holds, and how hard the pump has to work to move it. Get the volume and the head height right and you land on a sensible pump the first time, instead of buying twice.

    Start with the volume, not the pond

    Measure length, width and average depth in metres, multiply the three together, then multiply by 1000. That gives you litres. A pond three metres long, two metres wide and half a metre deep on average holds about 3000 litres.

    Average depth is the bit people fudge. Most backyard ponds have a shallow planting shelf around the edge and a deeper section in the middle, so the average sits well under the deepest point. Use the deep measurement and you will overstate the volume, sometimes badly.

    If the pond is an odd shape, break it into rough rectangles and add them up, or read your water meter before and after filling. Filling a new pond is the one time you get an exact figure for free, so write it down somewhere you will find it again.

    The turnover rule of thumb

    The working rule most pond people use is to circulate the whole volume once an hour. So a 3000 litre pond wants a pump moving roughly 3000 litres per hour. That figure keeps water passing through the filter often enough to stay clear and keeps oxygen moving.

    Adjust it for what is living in there:

    • Lightly planted ornamental pond, no fish: turning the volume over every two hours is usually plenty.
    • Standard mixed pond with a few goldfish: once an hour is the safe default.
    • Koi pond: koi are heavy waste producers, so aim for a full turnover every hour as an absolute minimum and size the filter to match.

    Turnover is really about the filter doing its job, and our guide to pond filtration and UV clarifiers covers how the two decisions fit together.

    Head height is where most people come unstuck

    Pumps are advertised at maximum flow, which is what they deliver pushing against nothing at all. Ask one to lift water and shove it through pipe and the flow drops away. Ignore that and a pump rated at 6000 litres per hour turns into a dribble at the top of your waterfall.

    Total head is two things added together. Static head is the vertical distance from the pond surface up to the point where the water pours out. Friction loss is everything the water fights on the way: metres of pipe, every bend, the filter, the UV unit, any fittings that pinch the flow down.

    You cannot calculate friction loss precisely in a backyard without a chart, so add a sensible allowance. On a short run of correctly sized pipe with a couple of gentle bends, half a metre to a metre on top of the vertical rise gets you close enough. Then read the pump’s performance curve, which every decent manufacturer publishes, at that total head figure. That number is the one that matters.

    A waterfall changes the sum entirely

    Once a waterfall or spillway is involved, flow gets judged by the eye, not the filter. A wide spillway with not enough behind it looks like a leaking gutter.

    The starting point widely used in the trade is around 1500 litres per hour for every 10 centimetres of spillway width, which gives a modest sheet. Want a thicker curtain that reads as a proper waterfall? Roughly double it. A 40 centimetre spillway on that basis wants somewhere near 6000 litres per hour.

    Now compare that against your turnover figure and take whichever is larger. The 3000 litre pond above wanted 3000 litres per hour for filtration, so the waterfall governs. If that number costs more to run than you are willing to wear, narrow the spillway rather than starving it.

    Plumbing choices that quietly cost you flow

    • Pipe diameter: go one size up from the pump outlet rather than down, because narrowing the pipe costs you more flow than any other single decision.
    • Sweep bends over sharp elbows: each tight elbow behaves like several extra metres of pipe.
    • Short runs: every metre of hose between the pump and the waterfall is friction you paid for and never see.
    • A valve on the outlet: fitting one lets you trim a slightly generous pump back to the look you want, which is far easier than living with one that is undersized.

    Whether the pump sits in the water or beside it is a separate decision with its own tradeoffs, and we have walked through that in the guide on submersible versus surface pumps.

    Putting it together

    Take that 3000 litre pond with a 40 centimetre spillway sitting 1.2 metres above the water and six metres of pipe running to it. The flow target is 6000 litres per hour because the waterfall governs. Total head is 1.2 metres of lift plus an allowance for pipe, bends and filter, so call it two metres. You are shopping for a pump that still delivers about 6000 litres per hour at two metres of head, which is a noticeably bigger unit than one whose box says 6000.

    Where the do it yourself part stops

    Plugging a pump into an existing weatherproof outdoor outlet is a homeowner job. Installing that outlet, running a new circuit or hard wiring anything is licensed electrical work everywhere in Australia, so it goes to a licensed electrician. Your state or territory electrical safety regulator is the authority on what needs a licence and what protection the circuit requires.

    Sizing is far easier when the pond gets designed around the pump, which is why pump position comes up early in the step by step guide to building a garden pond. And if the pond will sit near where small children play, ask your local council about barrier requirements before you dig, because the rules vary by state and by depth.

  • Koi and Fish Pond Basics: Keeping Fish Healthy in an Australian Backyard Pond

    Koi and Fish Pond Basics: Keeping Fish Healthy in an Australian Backyard Pond

    Ask most people why the fish in their backyard pond died and they will blame a disease. Nine times out of ten it was not a bug at all. It was the water. Get the water right and healthy fish largely look after themselves, so that is where a beginner should put nearly all their attention.

    Here is what actually keeps koi and goldfish alive and well in an Australian backyard: enough water, enough oxygen, a filter that has had time to mature, sensible feeding, and a bit of protection from summer heat and hungry birds. Work through those in order and you will dodge the mistakes that catch nearly everyone starting out.

    Give them more water than you think they need

    Fish are far more forgiving in a big body of water than a small one, because a larger volume dilutes waste and holds a steadier temperature. A tiny ornamental pond heats up fast on a hot day and crashes cold on a still night, and those swings stress fish badly.

    As a rough guide rather than a hard rule, keep your stocking light. Beginners almost always want too many fish too soon, and an overstocked pond is the most common reason water goes bad. Koi in particular grow big and live for decades, so a handful of little ones today can become a serious load in a couple of years. Depth helps too: a deeper section gives fish somewhere cooler in a heatwave and steadier through winter. If you are still planning, our step-by-step guide to building a garden pond covers sizing and depth before you dig.

    Oxygen: the thing beginners forget

    Fish breathe dissolved oxygen, and warm water holds a lot less of it than cool water, which is why gasping at the surface on a hot, still morning is such a common panic. The fix is movement. Anything that breaks the surface, a small fountain, a waterfall, or an air pump with an airstone, pulls oxygen into the water.

    A few things worth knowing about aeration:

    • Run it through the night in summer: plants and algae consume oxygen after dark, so the lowest oxygen of the day is usually just before dawn.
    • Surface agitation beats depth: gas exchange happens where water meets air, so a gentle ripple across the top does more than a jet firing into the deep.
    • Get the power done properly: any pump or aerator wired to a fixed outdoor power point must be connected by a licensed electrician. Plug-in and low-voltage solar kits are fine to set up yourself, but mains work is not a DIY job.

    The nitrogen cycle, in plain English

    This is the bit that quietly kills more fish than anything else. Fish produce ammonia through their waste and gills, and ammonia is toxic. In a healthy pond, colonies of beneficial bacteria living in your filter convert that ammonia into nitrite (still toxic) and then into nitrate (far less harmful, and taken up by plants).

    The catch is that a brand new pond has none of those bacteria yet. Fill a pond on Saturday and drop fish in on Sunday, and the ammonia has nowhere to go. Let a new pond run for several weeks so the filter can mature before you add stock, add fish slowly, and pick up a simple water test kit so you are reading the water rather than guessing. The filter is the engine room of the whole thing, so it is worth getting right. Our guide to pond filtration and UV clarifiers covers how to match one to your pond.

    Feed less, and never in the cold

    Overfeeding is the fast track to green, smelly water, because uneaten food rots and spikes ammonia. The old rule holds up: only give them what they will clean up in a couple of minutes, and once a day is plenty for most backyard ponds. Fish are cold-blooded too, so as the water cools through autumn their metabolism slows right down and they can barely digest. Once it is genuinely cold, ease off and then stop feeding over winter, or you are just leaving rotting food in a pond that can least handle it.

    Surviving an Australian summer

    Heat is the big seasonal risk. Hot water holds less oxygen, evaporates faster, and pushes fish to their limits. A few sensible moves take the sting out of it:

    • Throw some shade: floating plants like water lilies, or a shade sail over part of the pond, keep the water cooler and give fish somewhere to hide.
    • Top up gently: evaporation concentrates everything in the water, so keep the level up, and if you top up with town water let it stand or treat it for chlorine first.
    • Beat the birds: herons, kookaburras and the neighbour’s cat all fancy a feed, so a deeper zone, overhanging plants or netting gives fish a fighting chance.

    Reading the warning signs

    Fish tell you when something is off, usually well before it turns into a disaster. Watch for gasping at the surface, fins clamped tight against the body, flashing (rubbing against rocks), or fish going off their food and sitting listless on the bottom. The first response is nearly always the same: test the water and improve the oxygen. A partial water change and more aeration fixes a surprising number of problems.

    If fish stay sick after you have sorted the water, or you are seeing sores, ulcers or clear signs of parasites, get proper advice rather than throwing random medications at the pond. An aquatic vet or a specialist aquarium supplier can identify what you are dealing with and dose it correctly. Guessing at treatments does more harm than good.

    Plenty of water, steady oxygen, a mature filter, restrained feeding and a little seasonal common sense will carry a backyard pond full of healthy fish for years. For the bigger picture on pumps, ponds and water features around the garden, start with our complete guide to water in the Australian garden.

  • Pond Filtration and UV Clarifiers: How to Get Clear, Healthy Pond Water

    Pond Filtration and UV Clarifiers: How to Get Clear, Healthy Pond Water

    Answer first: green, cloudy pond water almost always comes down to filtration that isn’t keeping up with the muck and nutrients in the water. Get three things working together, mechanical filtration, biological filtration and, when algae is the culprit, a UV clarifier, and most backyard ponds clear up and stay that way. Here’s how the pieces fit, sized to your pond and the fish in it, without any guesswork about wattage or flow rates you don’t need.

    Why pond water turns green

    Green water is a bloom of single-celled algae, and it feeds on two things: sunlight and nutrients. The nutrients come from fish waste, uneaten food and leaves breaking down on the bottom. As that organic matter rots it releases ammonia, which is toxic to fish. Helpful bacteria convert the ammonia into nitrite, then into nitrate, which plants and algae then lap up. That chain is the nitrogen cycle, and it is the engine room of every healthy pond.

    So a green pond usually means one of two things: too many nutrients going in, or not enough biological filtration to process them. Balance that out and you starve the algae of what it lives on.

    Mechanical vs biological filtration

    These two do completely different jobs, and a good filter setup runs both.

    • Mechanical filtration: traps the physical gunk, leaves, fish waste and sludge, on foam pads, brushes or a fine screen. This is the part you rinse out regularly.
    • Biological filtration: gives those helpful bacteria somewhere to live. Porous media like bio-balls, ceramic rings or filter matting has a huge surface area, and the bacteria colonising it are what quietly turn toxic ammonia into far safer nitrate.

    Mechanical media you clean often. Biological media you leave well alone as much as you can, because scrubbing it hard kills off the colony you spent weeks growing. A gentle swirl in a bucket of pond water is plenty.

    What a UV clarifier does, and what it doesn’t

    A UV clarifier is a sealed tube with an ultraviolet globe inside. Pond water pumped past the globe cops a dose of UV light, which clumps the free-floating algae together so your mechanical filter can finally catch it. Run it for a week or two and pea-soup water usually turns clear.

    Here is the catch. A UV clarifier only deals with the green algae floating in the water. It does nothing for the stringy algae clinging to your rocks, and it is not a filter on its own: it only works with water flowing through it and a filter downstream to trap what it clumps together. It also won’t fix the underlying nutrient problem, so pair it with proper biological filtration rather than leaning on it alone. If you want to look at the buying options, a compact unit like a Pond One Cleartech UV steriliser suits a typical backyard pond, and it still needs a pump to push water through it. (As an Amazon Associate we earn from qualifying purchases.)

    Matching filter and pump to pond size and fish load

    The honest answer is that bigger is safer than smaller. A filter rated for a larger pond than yours will still cope on a hot day when the fish are active and the water is working hardest. Undersize it and you will be forever chasing green water.

    Two things drive the sizing:

    • Pond volume: roughly how many litres of water you are holding.
    • Fish load: a pond stocked with koi produces far more waste than a couple of goldfish, so it needs more filtration for the same volume.

    The pump is what ties it all together, because it has to move enough water through both the filter and the UV unit to actually turn the pond over. A reliable submersible unit such as a Platypus pond and fountain pump sits down in the pond and pushes the water up to the filter. Match the pump to the filter’s needs and the UV globe’s flow window, rather than grabbing the biggest one on the shelf.

    Flow, plumbing and placement basics

    Keep the plumbing short and simple. Every extra bend and metre of hose robs you of flow. Sit the filter slightly above the water line where you can, so it drains back cleanly, and keep the UV unit out of direct sun so the housing doesn’t cook in the afternoon.

    One thing that is not a DIY job: the power. Any pond pump or UV clarifier has to run off an outdoor power point on an RCD-protected circuit, and that connection is work for a licensed electrician. Water and electricity sitting next to each other is exactly where you don’t cut corners.

    Seasonal cleaning and keeping it running

    A pond filter is a living thing, so treat it like one.

    • Weekly in summer: rinse the mechanical pads and check the pump inlet isn’t blocked.
    • Every month or so: wipe over the UV globe housing, since a filmed-over sleeve blocks the light that does the work.
    • Once a year: UV globes lose their punch long before they stop glowing, so plan to swap the globe about yearly even if it still lights up.
    • Autumn: net the leaves off the surface before they sink and rot, which is the single best thing you can do to keep spring water clear.

    Get the filtration right, keep the flow steady and stay on top of the cleaning, and clear, healthy pond water stops being a battle. For the bigger picture on how ponds sit alongside pumps and the rest of the garden, have a read of our guide to water in the Australian garden, and if you are still planning the pond itself, start with how to build a garden pond.

  • How to Build a Garden Pond: A Beginner’s Step-by-Step for Australian Backyards

    How to Build a Garden Pond: A Beginner’s Step-by-Step for Australian Backyards

    Building a garden pond is well within reach for a weekend-handy homeowner: choose a level, partly shaded spot, decide how big and deep you want it, dig and shape the hole, line it, add water movement, then plant it and let it settle. The two parts to leave to professionals are the pump’s electrical connection (a licensed electrician) and checking whether your council has depth or fencing rules. Here’s how it comes together.

    Choosing the spot

    The right position makes everything easier. Look for somewhere that gets a few hours of sun but isn’t baking all day — too much sun feeds algae, too little starves your plants. Avoid the lowest point of the yard where stormwater runoff and garden chemicals will wash in. A reasonably level area saves you a lot of grief when it comes to getting the water line even.

    Safety matters too. If young children use the garden, think carefully about open water. Some councils treat ponds over a certain depth like pools and may have fencing or barrier requirements, so check your local council’s rules before you dig.

    How big and how deep

    Bigger ponds are actually more forgiving — a larger volume of water stays more stable in temperature and chemistry than a tiny one. For depth, you generally want a deeper zone so the water doesn’t overheat in summer and so fish, if you keep them, have somewhere cooler to retreat. Shallower margins around the edge give plants a home and let wildlife get in and out. There’s no need to chase exact figures; scale it to your yard and how much maintenance you’re happy to do.

    Flexible liner vs preformed shells

    You’ve got two main ways to hold the water. A flexible liner lets you make any shape and size you like and tends to suit larger, natural-looking ponds; it’s draped into the hole and shaped as you go. A preformed shell is a rigid moulded pond you drop into a matching hole — quicker and simpler for a small pond, but you’re locked into its shape and size. For a first pond, a preformed shell is the easy option; for something organic and bigger, a liner gives you freedom.

    Digging, shelving and edging

    Mark the outline, then dig in stages, cutting a shallow shelf around the perimeter for marginal plants and a deeper central zone. Remove sharp stones and roots, and add a layer of sand or underlay to protect a liner. Set your liner or shell, check the rim is level all the way round, then fill slowly so it settles into shape. Finish the edge with rocks, pavers or plants to hide the liner, hold it down and create a natural transition into the garden.

    Water movement: why most ponds need a pump

    Still water tends to go stagnant, grow algae and lose oxygen. A pump keeps water circulating — running a small fountain, a spillway or a filter — which keeps it clearer, better oxygenated and healthier for fish and plants. Choose a pump suited to your pond’s size and what you want it to do, whether that’s a gentle ripple or a proper waterfall.

    Position and plumb the pump yourself if you like, but the electrical connection must be done by a licensed electrician, on an outdoor RCD-protected circuit. Mains power beside a body of water is exactly the situation those rules exist for — it’s not a DIY step.

    Planting and letting it settle

    A new pond needs time. Add a mix of plants — submerged oxygenators, marginal plants on the shelves, and a floating-leaf plant or two for shade — and then be patient. The water may go cloudy or green at first while it finds its balance; that’s normal. Hold off adding fish until the pond has settled for a few weeks and the plants are established. Top up with rainwater where you can, and resist the urge to fiddle. Within a season most ponds find their rhythm.

    A pond is one piece of the bigger water picture — see how it sits alongside pumps, features and water-wise design in our guide to water in the Australian garden.