Tom ORP is a tough one to explain. Most people use a controller/monitor to keep an eye on Ozone generators. But here is a short and kinny explaination of it. Constantly in your tank thier is a battle going on between reducers (mostly bacteria reducing nutrients and so on) and Oxidizers. If either side whens the battle your tank dies, so you want it to be a balanced and never ending battle. Each side has thier big tough guys, for the oxidizers it would be ozone, big nasty and all oxidizing, on the other end in the SRB bacteria, they ae the same but reduce instead of oxidize. Your measure of orp is to keep an eye on the battle, ozone can be used to tilt the balce one way and co2 can be used to create an enviroment where the reducers have the advantage. The main thing you are trying to do is to keep the battle fair and unending. An experiment to show you would be to stick the ORP in your dsb (a few inches down) and watch the orp go straight down.
Hey, really? What does ORP, stand for? Not to sound stupid but knoledge is power and I could use the wattage. by the way could anyone hand out the manual of all the abb... terms ? I feel left out . this is the best board i've found. thanks for all the info.