What you need to know before buying a septic tank

Choosing a septic tank is not only a technical decision, but also an administrative and practical one. To choose correctly, three things matter: how many people live in the home, what type of soil you have (whether it allows drainage) and where the water goes after the septic tank. Below you will find the right models for each situation, with direct links to the products.

1. Which septic tank to choose, by number of people

The septic tanks below discharge to drainage (an infiltration field or percolation tunnel). They are suitable when the soil is sandy or loamy and water soaks in easily.

For 2–4 people (small house, holiday home)

ECO Imhoff 4 septic tank2–4 people · the most compactView product →ECO Water 2.0 septic tank2–4 people · 2,000 L, two chambersView product →ECO Bunker 2000 L septic tank2–4 people · 2,000 L, three chambersView product →

For 4–6 people (family, permanent home)

ECO Imhoff 6 septic tank4–6 people · Imhoff settlingView product →ECO Water 3.0 septic tank4–6 people · 3,000 LView product →ECO Bunker 3000 L septic tank4–8 people · 3,000 L, three chambersView product →

For 6–11 people (large house, small guesthouse)

ECO Imhoff 10 septic tank8–10 people · 1,500 LView product →ECO Water 5.0 septic tank8–11 people · 5,000 LView product →

For guesthouses, restaurants or buildings with more users, see ECR Grand industrial septic tanks and the page solutions for hospitality and tourism.

2. If the soil does not allow drainage or you want to discharge treated water

• Clay soil, high water table, small yard – choose a holding tanksolution without drainage: a watertight tank that is emptied periodically. Also read when a septic tank without drainage is the right choice.
• You want to discharge water into a stream, ditch or watercourse – you need a treatment plant with activated sludge, which treats the water much better than a conventional septic tank.

Grand 10000 L underground tankholding tank · 10,000 LView product →ECO FA 5 treatment planttreatment plant · 4–6 peopleView product →ECO FA 10 treatment planttreatment plant · 6–10 peopleView product →

3. The hassle-free option: septic tank with installation included

If you do not already have an installation team, choose a complete package with installation. It includes the septic tank, excavation, 10 m of drainage, the bioactivator and commissioning.

ECO Imhoff 4 package with installationpackage · 2–4 peopleView product →ECO Imhoff 6 package with installationpackage · 4–6 peopleView product →ECO Imhoff 10 package with installationpackage · 6–10 peopleView product →

4. What to tell us before ordering

To recommend the right model, we need:

• the number of people in the household (or the daily wastewater flow);
• the soil type (clay, sandy, loamy) and whether water appears in the pit when digging;
• the depth at which the drain pipe leaves the house;
• the distance from the house, well and property boundary;
• whether you have room for drainage or prefer a holding tank.

With this information we avoid undersizing and problems after installation.

5. Useful accessories for installation

If the septic tank is installed deeper, you need an extension collar for the manhole. For soils where there is no room for conventional drainage, percolation tunnels disperse the water over a smaller area. See all septic tank accessories.

Manhole extension collar 60 cmmanhole extension · 60 cmView product →APOLLO 150 percolation tunnelpercolation tunnel · 150 LView product →Ecofosa bioactivatorsbacterial start-up and maintenanceView product →

6. What to do (and not do) after installation

• Fill the septic tank with water before burying it and add the bioactivator at first use.
• Schedule emptying – usually every 2–4 years, depending on use.
• Do not connect the plumbing until installation is fully complete.
• Do not store heavy objects or drive over the septic tank unless it has a concrete chamber and a load-bearing cover.
• Do not use harsh chemicals (industrial chlorine, non-biodegradable detergents) – they destroy the bacteria that treat the water.

Need help choosing?

Write to us via the contact page or call +40 741 228 382 and we will recommend the right model, with price and delivery time.