In order for my osmolator nano to work, I have to unplug it, then once I plug it back in, it senses the low level and runs the pump. I have already shimmed the float sensor. The float is installed in the return chamber of my sump for my 40 gallon tank. I bought it new about 3 months ago and it worked great in the beginning, then I noticed that the level would be low and wouldn't pump at all. It's not a problem with it taking too long to top off the level, the return chamber is not large and takes about 10-20 seconds. There is an issue with the controller itself, pump and float work fine once I re-power the system.