@GeoSquid...trying to get the ATS going in a separate tub to incorporate into the main system was exactly what I was originally scratching my head about and seemed like a good idea but had difficulty learning about what to add to add, how much, how often, etc. in that environment, hence, the origin of this thread. If there were a simple way to do it I’d think ATS manufacturers would spread the word as I’m sure many people are incorporating an ATS into a new system (not only established ones) and I know I’m not the only one who would prefer to minimize/avoid new tank algae blooms if there is an alternate way that will also benefit the establishment of a viable long term filter. So, long story made short, I’m totally on board with you and FWIW, based on the input of many, I’m less inclined to go the urea route after all and may just stay lights out or dimly blue in the DT with very slow livestock additions hoping to have the ATS gain strength that way. Anything more involved is something I’d wager I’ll be sure to botch. Thanks for hopping in...much appreciated.