@ForbiddenDreamer @Jean_Philippe_Micheaux @sickburnbro i can handle a lobby fish aquarium, no problem. bump that up to two large pools, with the usual carbon/bone char/DE filters for water, it had the waste water components circling back into the "lilly pond" with some plant material going back to the tilapia. the algae and air contaminants took over (pollen, fire ash et al), tilapia got fungal spots, died, repeated cycles.