Underground Tank Neptun

ELKOPLAST NEPTUN underground tanks for rainwater and sewage treatment. Made of high quality polyethylene by rotational molding. The advantage compared to concrete tanks is easy transport and handling due to much lower weight. There is no need to concrete their casing, which significantly reduces installation costs. They are suitable for installation in sand, gravel and clay. NEPTUN underground tanks are fully self-supporting and certified.



  • for a 4300 and 6000 l tank, a shaft with a fixed height of 450 mm
  • for the 9500 l tank, a telescopic shaft in the range of 300-600 mm for easy adaptation to the ground surface
  • tank lid safe for children and adults(200 kg), optional mobile lid (600 kg)
  • made of food-grade polyethylene, without the need for concreting
  • expandable via interconnection system
  • tanks of 1 piece, seamless, ie without the risk of cracking the joint
  • easy handling due to low weight
  • with pre-prepared seals on the holes in the tank
  • certified, 20 year warranty



Type Length Width Height Volume Weight
Neptun 4,3 2300 mm 1700 mm 1850 mm 4 300 l 160 kg
Neptun 6 2450 mm 2040 mm 2050 mm 6 000 l 240 kg
Neptun 9,5 3000 mm 2300 mm 2 900 mm 9 500 l 400 kg


  • shaft, height 450 mm,
  • telescopic shaft, height 300-600 mm, adjustable,
  • lid with safety lock, load capacity 200 or 600 kg,
  • inflow set (filter, siphon, calmed inlet, fittings), parts available separately as well.

Delivered excluding installation. Individual elements of the inflow set can be ordered separately.


Suzan Šmídová photo

Suzan Šmídová
Contact our salesman!

Michal Forman photo

Michal Forman
Contact our salesman!

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