I don't know what your streams contain but if you want an idea what equipment is available for your volumes and your concentrations of COD, BOD, TSS, TDS and VOC's look at the US Filter web site which is a part of Siemans. You can also go to their website. There are some Technical Reports covering what I mentioned above. In my experience with SBR's if your stream has a large swing of concentrations or new components being introduced and others eliminated the "bugs" will not like you. It will even kill them. Then you are dead in the water (pun not intended). If your stream is consistent the "bugs" will love it and everything is fine. The cerodaphnia (I think that is the way you spell it) or flat head tests depend largely on the outfit performing the assay. Good idea to get two outfits at the beginning for comparison.