A few more posts from Gavin on his system etc. BTW he is using a model A with 12% peroxide and 2 catalysts.
"My Orp reading has almost always corresponded with my ph Levels, normally peak pH is the lowest ORP reading. The highest point on the Orp chart is approximately when the lights start to come on, and the lowest point approximately corresponds with the lights going off."
"with all the sumps, displays etc I'm around system volume of around 1,000 litres, tank is moderate/heavily stocked with fish, feed heavily probably equivalent to 7-9 cubes of frozen a day (I use slabs of frozen so cut my own cubes) and phyto is dosed during the day, and nori added every couple of days.
Filtration is provided by (in order of water travelling through them) an x-filter, skimmer, roaphos, carbon and siporax other then past the oxidator, I do also run a small cheato based refugium and one of the displays is half filled with caulerpa
My ORP I'm not 100% sure of, from memory it would start around the low 300's after a what change and rise slowly over the month to around mid to late 300's, so the oxidator definitely raises ORP and keeps it much more stable in my tank"
"I run one A model with two catalysts and 12% peroxide. The A only has a 250ml chamber so I have to refill about every 6 days, your larger model (model W) I suspect will do the same thing but with a larger chamber wont need to be refilled as often."