[tmz]

Ethanol is miscible. it will diffuse in the water readily. Perhaps more bacterial activity will occur in a reactor and less in the tank; perhaps not. The bacterial involved are mostly benthic ;so, they colonize surface areas. They consume some nitrate for food and some in anearobic activity. They also consume organic carbon and PO4 for phospho lipids , no matter where they grow. For me dosing 1/2 upstream from a can full of live rock serving as a cryptic refugium and the rest into a high flow area of the sump works well to limit unwanted stringy bacteial mass in the display tanks.

Steady alkanity is important ,ime. Swings even within acceptable ranges seem to occasion stn. FWI I've been dosing vodka and vinegar for 4 years with alk very constant in teh 8.9 to 9.6 range without stn and with good color and growth.