Dr Elaine Ingham, who is generally regarded as an expert of teas, recommends in her book 'The Compost Tea Brewing Manual' to not dilute tea more than 10-1. Tea's are not like nutrients, they do not require a specific dilution rate. The water is really just a 'carrier' for the micro-organisms. I dilute mine usually about 5-1, but the rate depends on how much area I need to cover. If I am just drenching a few plants and I don't need much, I'll use it straight. If I have to do a large area I will up the dilution to however many gallons I need to cover said area.