In parallel with the heightened interest in constructed vertical flow (VF) reed bed solutions in the UK it could be argued that there is growing confusion to the design, construction and effective purification process to potential interested clients. An ideal ‘one fits all’ benchmark may be seen to be impossible as each VF reed bed requires addressing specific situational and operational criteria. No British Standards (BS EN) outlining vertical flow reed bed technical design exist other than in the form of BRE Good building Guide (GBG42).There are also other guides available from the Soil Association and Environmental Agency including individual experts, private companies and specific publications. The reed bed market may seem to observers to be made up of a group of individual experts with their own proven theories and methods to how a reed bed should effectively work. In reference to settled domestic wastewater two initial pieces of information that are relevant to the client are usually concerning the size of VF reed bed system, per person/m2/perday required and the daily flow rate per person per day to keep the system effective. Even at this initial evaluation stage there are very different calculations to size and flow required. A certain water company recommended 200 litres per person/m2 per day whilst another private company suggested up to 300 litres. In relevance to the wider environmental debate are 800+ litre volumes required daily to maintain an effective VF reed bed say for a family of four. Even with expected higher peak loads or effectively building the reed bed to larger dimensions a minimum benchmark to how much flow rate per person is required may minimise the overall flow rate specifications expected nationally. I wish to test VF reed beds using a flow rate of just 100 litres/m2/per person per day and see if they conform to Environment agency discharge consent criteria. The purpose of this thesis is to make a comparative study of four different sized VF reed beds utilising the same flow rates 100L/pp/m2/perday to test for purification standards of settled domestic wastewater. The VF reed beds are potentially: 4m2 400 litres per day 50m2 5000 litres per day 100m2 10000 litres per day 200m2 20000 litres per day Materials and methods: The domestic wastewater The VF reed bed system Operation of the system including seasonal temperature Sampling and measurements This comparative study shall use the following sampling and measurements to carry out a variety of water purification tests on each reed bed. Palintest/ colorimetric analysis tests for ammonia, nitrates and phosphates removal and reductions for the outflow only to measure for Environment Agency discharge consent criteria, (20mg/l BOD + 20 mg/l solids). Permanganate value (PV): indicating the general quality of final effluents and enabling PV to be determined and the effluent classified as to its acceptability for discharge. pH Test: Chemical and biological reactions are profoundly influenced by pH. A pH test shall check for any effect of acid or alkaline in the effluent flow. Turbidity test to give a measure of the Suspended solids (SS) content of the final effluent. It is possible to derive an indication of the COD (Chemical Oxygen Demand), BOD (Biochemical Oxygen Demand) and TOC (Total Organic Carbon) from the permanganate Value test. This is based on the relationship between these measures of organic pollution experimentally for domestic sewage and effluents. Research is carried in Leeds from yes reed beds run by Melvyn Rutter. Notes: Permission from Melvyn Rutter to take any information including photographs from www.yes-reedbeds.co.uk