Water. Drink more and drink good quality, pure water. It is as simple as it sounds. Our bodies are around 70% water and it is recommended that you drink 30ml per kilogram of body weight.
For precisely this purpose, we're giving away a stainless steel water bottle (that lovely looking bottle to the left) with every 3 and 5 day cleanse delivered from today until we run out (we have around 500 to give away, give or take the few that I will keep for myself).
According to Wiki (the source of all arguable truth), in 2004 only 42% of the world's population had access to clean water. So in Australia we are incredibly fortunate to have access to such good quality water, though you can do better than tap water and we believe it's worthwhile investing in a good quality water filter.
Good water filters remove bacteria and toxins (and make your water taste nicer!). Purifying your own water is also much cheaper and better for the environment than buying bottled water.
To make our Spicy Lemonade and Cashew-coco smoothie, we use water filtered by our beautiful clay water filter from Southern Cross Pottery. Upfront, they are not cheap, costing from $229 upwards, however the replacement filter lasts for 12 months or 2000 litres and the water costs 11.5c per litre in the first year and 2c per litre thereafter. The water is honestly the best I've tasted and I've also invested in one for home. I know I sound like an infomercial, but I promise I have no friends there and I'm getting no kickbacks (yet, anyway).
Not quite as effective or cheap in the long run, but very easy and convenient, are the Brita OnTap filters, available from Kmart, Target, etc.