Promax Tools

Make specifying the right Slimline tank system effortless. With this tool, you can:

Quickly select the correct install detail, PS1 documentation and typical plumbing schematic for your site
Access our BIM library with the click of a button
Answer a few short questions about site conditions and get the right files in seconds

No more scrolling through dozens of drawings or hunting for the right spec — streamline your workflow, reduce consent headaches, and keep your schedule moving.

Use our free Selector Tool to match your Promax underground tank to a certified installation drawing.
 

Installing a tank below ground is never one size fits all. Soil type, traffic loading and cover depth all influence the detail you need. Rather than sift through 23 drawings, let the Selector Tool do the work for you:

• Filters every certified Promax installation option
• Aligns with New Zealand load cases from light landscape to HGV traffic 
• Flags minimum and maximum burial depths 
• Gives you an instant download link for your drawing register  

Answer a few quick questions and the calculator will present the exact detail for your site. No guesswork. No delays.

This tool provides a simplified, conservative estimate aligned with AS/NZS 1547. It is intended for preliminary guidance only. Septic tank sizing varies by council, site conditions, and designer requirements.
We recommend confirming minimum tank volumes with the relevant Territorial Authority and undertake site-specific assessment where required. If in doubt, seek professional guidance from a suitably qualified wastewater designer.

Choosing the right water tank shouldn’t be guesswork. Our Tank Size Calculator makes it simple. Just enter your roof area, location, and rainfall data, along with your household’s known or estimated water use.

The tool will calculate the ideal tank capacity to keep your property supplied year-round, with the option to include extra drought protection for peace of mind.
 

Start planning smarter, save time, and ensure you’ve got the right storage from day one.

This calculator lets engineers, installers and specifiers choose a tank model and detention volume to see the exact partial volume and critical levels.

Use this tool to find out how far below finished ground level the orifice will be, depending on your selected tank size and detention volume.
 

The results help you plan pipework, set invert levels and confirm compliance long before you break ground.

Navigating the complexities of stormwater regulations in SMAF (Stormwater Management Areas: Flow) areas can be challenging.

Promax’s SMAF Calculator is designed to simplify compliance with Auckland’s stormwater detention and retention requirements.

By referencing the expert insights, our calculator ensures your project adheres to environmental standards while promoting sustainable development.

Discover the ease of stormwater calculation with Promax. Simply fill out all the relevant data points below and print your SMAF calculations below.

Attenuating stormwater runoff on complex sites can be challenging. Promax’s Pre-Post calculator will generate your own Stormwater Report quickly and efficiently, whilst sizing and locating the orifice at the same time.

Discover the ease of stormwater calculation with Promax. Simply fill out all the relevant data points below and print your stormwater report below. Note, if you need to find your rainfall data, get the HIRDS data here.