When it comes to septic tanks in New Zealand, there is no room for compromise. Hygiene and safety are paramount, and the structural integrity of the tank has to be flawless. That’s precisely what you get in every Promax septic tank. Our ‘Single Stage’ filtered septic tanks are designed by geotechnical experts and manufactured to meet the stringent standards for New Zealand septic tanks. Each heavy-duty ribbed tank we sell is fully tested to withstand ground and water pressure at depth, yet for all its strength, it is lightweight, meaning you’ll save on transport and installation costs. And as you’d expect, every tank is completely internally plumbed up to the outlets.