Now, i posted this link in the OC forums, it has some interesting info about glycol and oxidation, they promote their onw stuff but it´s interesting reading thou, you find their articles under "helpfull articles" Some other intersting thing is their own product called "Coolflow IG" a Mono ethylene glycol with anticorrosion, scale and algae inhibitors. Maybe some of you from the UK could find this stuff and try it out.
So far i havent seen any glycol brands that states that they have scale and algae inhibitors. Maybe those articles are some explenation to why glycols works for some people and not for others?
Link :
Hydratech Chemicals