Building a garden pond transforms your outdoor space into a natural habitat. DIY material costs: €200–€2,000 depending on size. Landscaper: €800–€5,000.
What Does a Garden Pond Cost? DIY vs. Landscaper
| Pond Size | DIY (materials) | Landscaper (materials + labour) |
|---|---|---|
| Small pond (1–2 m², liner) | €150 – €400 | €600 – €1,500 |
| Medium pond (3–6 m², liner) | €400 – €900 | €1,500 – €3,500 |
| Large pond (8–15 m², liner) | €800 – €2,000 | €2,500 – €6,000 |
| Preformed basin (1–3 m²) | €200 – €700 | €600 – €1,800 |
| Natural pond (no liner) | €300 – €1,500 | €1,500 – €5,000 |
Pond Liner vs. Preformed Basin
Pond Liner (EPDM or PVC)
- Completely flexible in shape and size
- EPDM: 0.8–1.5 mm thick, lifespan 30–50 years
- PVC: 0.5–1.0 mm, cheaper, lifespan 10–20 years
- EPDM price: €5–€12 per m²
- PVC price: €2–€6 per m²
Preformed Basin
- Fixed shape from polyethylene or polypropylene
- Simple installation
- Limited shapes and sizes — max. approx. 3–4 m²
- Good value for small ponds
- Price: €100–€600
Choose a preformed basin if you want a small pond (max. 1,000 litres) and want to get it done quickly.
Choose pond liner if you want a larger pond or a free-form shape. EPDM liner is the best choice: thicker, stronger, and lasting up to 50 years.
What You Need for a Garden Pond
Pond Pump and Filter
| Pond Size | Pump Capacity | Price |
|---|---|---|
| Small pond (up to 2,000 L) | 1,000–2,500 L/h | €30 – €80 |
| Medium pond (2,000–5,000 L) | 2,500–6,000 L/h | €60 – €150 |
| Large pond (5,000+ L) | 6,000–15,000 L/h | €100 – €400 |
Rule of thumb: pump capacity (L/h) = pond volume (L) × 0.5–1.0
Filter Types
| Filter Type | Price | Best for |
|---|---|---|
| Internal filter | €20 – €80 | Small pond without fish |
| External pressure filter | €60 – €300 | Pond with fish |
| Flow-through filter | €80 – €400 | Medium to large pond |
| Combined pump + UV clarifier | €100 – €500 | Pond with many fish |
Materials List: 4 m² Liner Pond (approx. 1,500 L)
| Material | Quantity | Approx. Cost |
|---|---|---|
| EPDM pond liner (1.0 mm, 4×4 m sheet) | 1 sheet | €80 – €200 |
| Pond underlay fleece | 6 m² | €20 – €40 |
| Pond pump (2,000 L/h) | 1 unit | €50 – €120 |
| External filter with UV | 1 unit | €80 – €200 |
| PVC hose (25 mm, 5 m) | 1 unit | €10 – €20 |
| Edging stones or pond edging slabs | 10 lin. m | €50 – €150 |
| Pond sand (substrate) | 50 kg | €15 – €30 |
| Aquatic plants (selection) | 10–15 plants | €50 – €150 |
Total materials: €355 – €910
Minimum Pond Depth
| Use | Minimum Depth | Why |
|---|---|---|
| Plants only | 40–60 cm | Shallow ponds freeze solid in winter |
| Goldfish | 60–80 cm | Fish overwinter at the deepest point |
| Koi carp | 100–150 cm | Koi needs volume and depth for health |
Always plan at least 80 cm at the deepest point if you want to keep fish.
Step-by-Step: Build a Garden Pond in 9 Steps
Step 1: Choose the Location
- At least 5–6 hours of sun per day (for aquatic plants)
- Not under trees – falling leaves block the filter
- Level and stable ground – the pond must not leak
- Electricity supply nearby for the pump (outdoor socket)
- At least 2 metres from trees and 1 metre from hedges
Step 2: Mark the Shape
- Draw the shape on the ground using a hose or sand
- For an organic shape: lay a rope on the ground and form it
- Score and mark the edge with a spade
Step 3: Excavate
- Dig the edge of the pond approx. 20 cm deep – this is the shallow marginal zone
- Dig the central area 50–80 cm deep – this is the deep zone
- Create stepped shelves (marginal zone, mid zone, deep zone) for different planting levels
- Remove all stones and roots
Pond depth:
– Planting pond (no fish): 40–60 cm
– Pond with goldfish: minimum 60–80 cm
– Pond with koi: minimum 1.20–1.50 m
Step 4: Lay the Underlay Fleece
- Check the base for stones, roots and sharp edges
- Lay underlay fleece fully over the pond excavation and up the sides
- Fold the fleece into corners rather than cutting it
Step 5: Lay the Pond Liner
- Lay the liner over the fleece
- Position the liner centrally over the pond
- Slowly fill with water – the liner will settle into the shape
- Smooth out folds at the edges as you fill
- Leave approx. 30 cm overhang at the edges
Step 6: Fill with Water
- Place a hose in the pond
- Fill slowly – the liner continues to settle
- Smooth folds as the pond fills
- Do not fill at full pressure (risk of tearing the liner)
Step 7: Secure the Edges
- Lay edging stones or large rocks on the overhanging liner
- Tuck the liner between the stones and fleece
- Trim excess liner after 2–3 days (not before)
- Safety margin: liner should overlap the pond edge by at least 30 cm
Step 8: Install Pump and Filter
- Position the external filter on the pond edge
- Place the pump at the deepest point of the pond
- Run the hose from the pump to the filter and back into the pond
- Electrical connection by a qualified electrician (use outdoor low-voltage circuit)
Step 9: Planting
Plant the pond in zones:
– Marginal zone (0–10 cm): Yellow iris, bulrush, marsh marigold
– Shallow water (10–30 cm): Water mint, arrowhead, sweet flag
– Deep water (30–80 cm): Water lilies, water pennywort
– Open water: Hornwort, water weed (oxygenating plants)
Fish in a Garden Pond: How Many and Which Species?
| Fish Species | Minimum Pond Size | Suitable for Winter | Notes |
|---|---|---|---|
| Goldfish (Carassius auratus) | 500 litres | Yes (down to -10°C) | Easiest pond fish |
| Koi carp | 3,000 litres | Yes | Needs more space and filtration |
| Rudd | 500 litres | Yes (native) | Good for wildlife ponds |
Rule of thumb: maximum 10 cm of fish per 100 litres of pond water.
Common Mistakes
| Mistake | Consequence | Solution |
|---|---|---|
| Too much sun | Algae bloom, green water | At least 30% shading by water lilies |
| No fleece under liner | Liner gets damaged | Always lay underlay fleece |
| Insufficient pump capacity | Cloudy water, fish suffer | Pump capacity = pond volume ÷ 2 per hour |
| Liner not secured at edge | Liner slips into pond | Lay edging stones on liner |
FAQs
How large does a pond need to be for fish?
For goldfish: at least 1,000 litres (approx. 2 m², 60–80 cm deep). For koi: at least 5,000–10,000 litres.
Does a pond need a pump?
For wildlife ponds without fish: not necessarily. For ponds with fish: always a pump and filter.
How do I prevent algae in the pond?
Introduce oxygenating plants, add water lilies for shading, install a UV clarifier, and do not overstock with fish.
Can I legally build a pond in my garden?
In most cases, no planning permission is needed. Check local rules for ponds larger than 100 m² or where groundwater may be affected.
Building Plans and Guides
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