Not quite site-wide but almost.
Example - water softening filters for Sunbeam Coffee machine - 4-pack $55.95 with 20% discount (add delivery $7.30) is $52.06
https://www.truwater.com.au/commercial-food-services/coffee-…
Use coupon code LDAY2017 at checkout. Coupon LDAY2017 activates 20% discount in your cart and should reflect under the total value*. Coupon validity 29/09/2016 at 5.00PM and ends 02/10/2016 at 11.59PM EST. Coupon code can be used multiple times until the promotion end date. Retail customers only. Discount does not apply to some selected already discounted products and excludes some products and categories.
"Example - water softening filters for Sunbeam Coffee machine"
Does anywhere in Australia actually have hard water? I know Sydney certainly doesn't, as I've never had to remove calcium deposits from my kettle.
It was an issue when I lived in Europe though.