He mixes 20L of each at a time & not sure on dose rate I'll ask
I see your point Layton but I'll stick with a reactor like PP I adjust the flow weekly & change the media annually (maybe) and parts for them are cheap the only thing to break is the impellor?
U forgot the cost of RODI to mix all the 3 part, Nick uses the 3 part on his system at home HEAVILY stocked sps 2000L and mixing the chems is a PITA he go's thru heaps of it using an Aquamedic triple dosing unit.