DIY GUIDE · GARDEN & OUTDOOR · CHECKED OCTOBER 2026
How to look after a garden pond yourself
An hour a month, half a day in autumn. €30–€45 in nets, gloves and buckets.
Leaves and blanket weed, plants, the filter, topping up, winter, and where it stops.
- Every step, start to finish
- Checked October 2026 — sources at the end
- Honest about when to call a pro
FIRST, THE HONEST ANSWER
Do it yourself, or get a repairer?
Do it yourself if…
- It is a small garden pond you can reach every part of from the edge
- The pump plugs into an existing outdoor socket protected by an RCD
- The job is routine care: leaves, weed, plants, the filter and topping up
- You can keep children away from the water while you work
Get a pro if…
- The pond needs emptying, a new liner or a leak finding
- The pump has no proper outdoor supply, or the cable or socket is damaged
- The pond is deep enough to be a drowning risk and children use the garden
- Fish are dying, or the water stays green and smelly despite routine care
Safety first
- Unplug the pump at the socket before you touch it, the filter or the cable, every time.
- Run pond pumps only from an outdoor socket with RCD protection; Safe Electric says an RCD that trips for no clear reason needs a Registered Electrical Contractor to check the installation, and any new outdoor circuit is restricted electrical work for one.
- Never leave children alone near a pond, even a shallow one; a toddler can drown in a few centimetres of water. Cover or fence the pond while children are small.
- Wear waterproof gloves and cover cuts. Pond water can carry leptospirosis from rat urine, which the HSA says enters through cuts and through the eyes, nose and mouth; wash your hands afterwards.
- Kneel on a board at the edge rather than stretching out over the water, and never wade in.
- Do not tip pond plants, weed or water into a stream, ditch or drain; some pond plants are invasive species and spreading them is an offence.
Stop here: Emptying or relining, any electrical change, and deep water where children play
Any new electrical supply or socket in the garden is restricted electrical work that only a Registered Electrical Contractor registered with Safe Electric may carry out, and the danger of water and mains electricity together is the reason. Emptying a pond moves fish, wildlife and many litres of water and silt, and spreading listed invasive plants is an offence under regulation 49 of the Birds and Natural Habitats Regulations 2011. Deep water is a drowning risk for young children that no routine care removes. How to hire a pond maintenance specialist →
| MATERIAL | COVERAGE | FOR THIS JOB |
|---|---|---|
| Pond netting | Fine mesh, sold by the metre or boxed | The pond's size plus about half a metre all round |
| Aquatic planting baskets | Mesh baskets with hessian or a liner | One per plant you divide |
| Aquatic compost and gravel | Heavy, low-nutrient compost and a gravel top | A bag per few baskets |
| Rainwater | From a water butt, for topping up | As much as evaporation takes in summer |
How much the pond holds
Volume in litres ≈ length × width × average depth in metres × 1,000. A pond 2 m × 1.5 m with an average depth of 0.4 m holds about 1,200 litres.
Use the volume to choose pump and filter sizes and to work out how much a top-up adds. Never change more than a small part of the water at once.
A fine net stretched over the pond and pegged at the edges in early autumn catches most leaves before they sink and rot. It is the single best piece of pond care, and much easier than fishing leaves off the bottom later.
Blanket weed winds round a stick or a rake like candyfloss. A long-handled pond net lifts floating weed and duckweed. Avoid chemical blanket weed treatments in a wildlife pond; balance the plants instead.
Oxygenating plants under the water, floating leaves such as water lilies over about half the surface, and marginal plants at the edge starve algae of light and nutrients. A pond with no plants goes green whatever filter it has.
The sponges in a pond filter are home to bacteria that keep the water clear. Rinsing them in a bucket of pond water cleans them without killing those bacteria; tap water, which carries chlorine, kills them.
Rainwater from a water butt is the best top-up because it is soft and has no chlorine. Tap water can be used in small amounts in an emergency, but during a Water Conservation Order a hosepipe may not be used to fill or maintain a domestic pond, other than a fish pond.
THE PART THAT DECIDES THE FINISH
Before you start — by the pond and the season
What a pond needs depends on the time of year and what lives in it. Find yours.
Spring
Water warming, plants starting to grow.
- Clean the pump filter once the water has warmed and the fish are active
- Lift, divide and repot plants that have outgrown their baskets
- Thin oxygenating plants that have filled the pond
- Leave frogspawn and tadpoles undisturbed
Summer
Fast growth, warm water, evaporation.
- Wind out blanket weed every week or two
- Top up with rainwater as the level drops
- Rinse the filter sponges when the flow from the outlet slows
- Remove yellowing leaves and spent flowers from marginal plants
Autumn
Leaves falling, plants dying back.
- Net the pond before the main leaf fall
- Cut back dying marginal plants above the water line
- Lift sunken leaves out gently before they rot
- Leave some plant stems standing as winter shelter for insects
Winter
Cold water, little growth, ice.
- Leave the pond alone as much as possible
- Float a ball on the surface so a hole can be kept in ice; never smash ice
- Take a pump that is not frost-proof out, clean it and keep it somewhere frost-free; store the filter sponges submerged in water indoors over a hard winter, as the filter maker advises
- Keep the net clear of snow and leaves
A pond with fish
Goldfish, koi or other fish kept in the pond.
- Clean the filter in pond water only, and never all of the media at once
- Do not feed fish when the water is cold
- Avoid any sudden change in water temperature or chemistry
- Leave major water changes or treatments to someone who keeps fish
THE JOB
The steps, in order
Check the pond, the season and the power
10 minStart with the checks above for the season. Walk round the pond and look at the water level, the colour, the plants, the flow from the pump and the state of the cable and the outdoor socket. Look for frogspawn, tadpoles, nesting birds in the marginal plants and any creature you might disturb. Then unplug the pump at the socket before you do anything else.
- Write down the date you last cleaned the filter
- A cracked socket cover or damaged cable is a reason to stop and call an electrician
- Keep children indoors while you work
Mistake to avoid: Reaching into the water to free the pump with the power still on.
Clear leaves and debris
15–30 minSkim floating leaves and debris off the surface with the pond net. Then lift out sunken leaves from the bottom slowly and gently, a little at a time, without stirring up all the silt. Leave the leaves on the edge on a sheet or in a tray overnight so frogs, newts and insects can crawl back into the water before you compost them.
- Do a little every few days in autumn rather than one big clear
- Lift, do not drag, along the bottom
- Stretch netting over the pond to stop the next lot
Mistake to avoid: Scooping out the bottom of the pond in one go and throwing away the creatures that live in it.
Wind out blanket weed
15 minPush a rake or a rough stick into the blanket weed and twist it slowly; the long threads wind round it like wool on a spindle. Lift it out and lay it on the edge overnight, like the leaves, so any creatures can return. Pull duckweed off the surface with the net. Take out only what you need to clear the surface; a little weed is food and shelter.
- Blanket weed is a sign of too much light and too many nutrients
- Add floating plants to shade the water
- Compost the weed once the creatures have left it
Mistake to avoid: Pouring a chemical blanket weed treatment into a pond full of wildlife and killing the oxygen with the rotting weed.
Clean the pump filter in pond water
20–30 minWith the pump unplugged, fill a bucket with water from the pond. Open the filter as its manual shows and lift out the sponges or media. Rinse them gently in the bucket of pond water, squeezing them a few times, until they are clean enough for water to flow through. Do not scrub them clean or rinse them under the tap. Refit them the right way round, facing the flow as the manual shows, close the filter and plug the pump back in.
- Clean when the flow from the outlet drops, not on a fixed date
- Rinse half the media one week and half the next if you keep fish
- Clear the pump's intake cage of weed while the power is off
Mistake to avoid: Rinsing filter sponges under the kitchen tap and killing the bacteria that keep the water clear.
Thin and divide the plants
30–60 minIn spring, lift any marginal or deep-water plant that has outgrown its basket. Lay it on a sheet, cut the root mass into pieces with an old bread knife or a spade, and replant one healthy piece in a fresh basket of aquatic compost topped with gravel. Thin oxygenating plants that have filled the water by pulling out a third of them. Put the extra plants on the compost or give them to a neighbour with a pond.
- Do not use ordinary garden compost; it feeds algae
- Top each basket with gravel so the compost does not wash out
- Lower baskets back in slowly so trapped air escapes
Mistake to avoid: Leaving the oxygenators to choke the whole pond, then pulling them all out at once.
Top up the water
10–20 minIn summer, the level drops through evaporation. Top up with rainwater from a water butt, a bucket or a can at a time, little and often. Small amounts of tap water are a last resort, and only when no hosepipe restriction is in force. If the level drops much faster than in neighbouring weather, there may be a leak.
- Mark the full level on a stone or a cane
- Rainwater is softer and has no chlorine
- Rapid loss of water is a reason to call someone in
Mistake to avoid: Filling the pond with a hose of cold tap water on a hot day and shocking the fish.
Cut back the marginal plants in autumn
20–30 minAs marginal plants yellow and die back in autumn, cut the dead stems off just above the water line with secateurs. Cutting below the water lets water into hollow stems and can rot the plant. Leave a few stems standing as winter shelter for insects and their larvae. Remove the cuttings so they do not rot in the pond.
- Cut on a dry day
- Drop the cuttings straight into a bucket, not the water
- Leave the evergreen marginals alone
Mistake to avoid: Cutting hollow stems below the water and rotting the plant over winter.
Prepare for winter
20 minNet the pond if you have not already. If the pump is not frost-proof, unplug it, lift it out, clean it and keep it somewhere frost-free. Store the filter sponges indoors submerged in water, as the filter maker advises, so the bacteria on them survive. Float a ball on the surface so you can lift it out to open a breathing hole if the pond freezes over. Never smash ice; the shock waves harm fish.
- Melt a hole in ice by standing a pan of hot water on it
- Do not feed fish once the water is cold
- Check the net after every storm
Mistake to avoid: Smashing the ice with a spade and stunning the fish underneath.
Check and record
5 minPlug the pump back in, if it is staying in, check the water is flowing and the RCD has not tripped, and walk round the pond once more. Note what you did and when in a notebook or on your phone. Next month's job is quicker when you know what last month's was.
- Press the RCD's test button now and then
- Watch the water's colour week to week
- Note the dates frogspawn appears
Mistake to avoid: Plugging in a pump whose cable you have just cut with the secateurs.
The mistakes that show
- Cleaning the filter under the tap and losing the clear water for weeks
- Doing one huge clean-out instead of little and often
- Letting leaves sink and rot every autumn
- Tipping surplus pond plants into a stream or ditch
Stop here and get a pond specialist
- The pond needs emptying, relining or a leak finding and fixing
- The pump needs a new supply, the cable or socket is damaged, or the RCD keeps tripping
- The pond is deep and young children use the garden
- Fish are dying or the water stays foul despite routine care
| WHAT YOU SEE | WHY, AND THE FIX |
|---|---|
| Green pea-soup water | Algae fed by sunlight and nutrients. Add floating plants to shade about half the surface, stop feeding fish so much, and give the filter time; do not empty the pond. |
| Long strands of blanket weed | Too much light and nutrient. Wind it out regularly, add plants, and keep fertiliser and lawn feed out of the pond. |
| Water level dropping fast | Evaporation in hot weather, or a leak. Top up with rainwater and mark the level; if it keeps falling with no hot spell, the liner may be damaged. |
| Pump running but little water coming out | A blocked filter or intake. Unplug, clean the intake cage and rinse the filter in pond water. |
| Foul smell and dark water | Leaves and plant matter rotting on the bottom. Lift them out gently over a few sessions and net the pond next autumn. |
| Fish gasping at the surface | Low oxygen, often on a hot, still night. Run a fountain or the pump for longer, and call a specialist if it continues. |
| RCD trips when the pump starts | A fault in the pump, cable or connection. Unplug it and have it checked; never bypass the RCD. |
| Plants taking over the pond | Vigorous plants left undivided. Lift, divide and replant one piece per basket each spring. |
WHAT YOU SAVE
What it costs to do it yourself
| Heavy-duty pond netting | €20.99 |
|---|---|
| Waterproof or grip gloves | €7.99–€9.99 |
| Buckets | €2.49–€4.98 |
| Fine netting by the metre, for a larger pond | €5.99 per metre |
| Total, first time | €31–€42 |
| DIY total | €30–€45 |
Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.
Routine pond care costs very little once you have a net and gloves. The expensive parts, a pump or a new liner, are for a specialist to advise on.
RATHER NOT?
Pond maintenance specialists near you, with prices shown
The ones who cover your area, nearest first, with one score from every review. No account needed to look.
Or post the job free and let them come to you.
Once creatures have left them, blanket weed, leaves and plant cuttings go on the compost heap or in the brown bin, which mywaste.ie lists for garden waste.
Never dump surplus plants, weed or water in a stream, a ditch or the countryside; give them away or compost them.
A pond pump is electrical waste. Bring it to a WEEE drop-off point or a civic amenity site; mywaste.ie lists both, and it must not go in the general bin.
Rinse gloves and nets after use and dry them; wash your hands well after any pond work.
Looking after a garden pond: questions people ask
Unplug the pump, then rinse the filter sponges gently in a bucket of pond water, not tap water. Chlorine in tap water kills the bacteria that keep the water clear.
Almost never. Routine care, clearing leaves, winding out weed, thinning plants and rinsing the filter, keeps a pond healthy. Emptying it harms wildlife and is a job for a specialist.
Rainwater is better. Small amounts of tap water are possible in an emergency, but during a Water Conservation Order a hosepipe may not be used to fill or maintain a domestic pond, other than a fish pond.
Shade about half the surface with floating plants, add oxygenating plants, keep the leaves out, and do not overfeed fish or let lawn feed wash in.
Only if the pond is fenced or covered with a strong mesh grid, and even then never leave children alone near it. Young children can drown in very shallow water.
The Locufy Irish price guide puts pond maintenance at €60–€250 per visit, typically €120. Ask whether the price covers taking away the silt and weed.
MORE GUIDES
More DIY guides
Sources — checked October 2026
- ProEco Products — Bio Flow filter manual: cleaning the foam pads in pond water, winter storage
- HSA — leptospirosis
- Safe Electric — home safety: RCDs
- Safe Electric — restricted electrical works
- Water Services Act 2007, section 56 — conservation of water
- European Communities (Birds and Natural Habitats) Regulations 2011, S.I. 477 of 2011 — regulation 49
- mywaste.ie — garden waste
- mywaste.ie — electrical gardening tools
- Woodie's — price check: pond netting
- Woodie's — price check: gloves
- Woodie's — price check: buckets