Nice job.
Truly fascinating thread!!! Might look into building one for my 180 Gallon. The makers of this micro c g stuff is in my neck of the woods too.
Have you tested the water lately to see if this stuff messed with your water parameters besides nitrate? I know I will be nowhere near you in terms of fish and tank, but how much have this micro c g have you used already and how much has this saved on the water bill (dunno what kind of percentage WC rate you had before with your auto-waterchanger if you care to tell us). I was wondering if the water collected from the wet/dry sump will be too oxygenated for the anoxic bacteria and if a circulation pump will be detrimental as well?