Every time I test my Phos levels they stay at 0.25 ppm. I have made a DIY protein skimmer that almost worked too well, and completely filled the collection cup in 3 days. Now I am running Aqueon Phosphate remover pads in my hob filters, and still no change. This is very confusing. The test used to change when I first set up my nano around a year ago, but when I first setup my 30g they stopped changing. It doesnt even change after a water change. Also keep in mind I have VERY heavy filtration