Sorry not to derale this thread but-
Just out of curiosity what are we considering smaller systems? Less than 500 gallons? In the posts that mention an osmolator is better for smaller systems are we saying that the rate of flow from the pump may not be sufficient to match evaporation rate of the system? I have an osmolator on a 120 Gallon tank with about 30 Gallons in the sump. Granted system size does not absolutely determine evaporation rate but mine isn't running that often that it is limited to the rate of the pump and I would love to have a system that had this problem