Latest full tank shot.
I use a 4 stage reverse osmosis filter system to create freshwater for dehydration top-ups and I hadn’t changed the filters since buying the unit in 2007 (!). Today I received a filter replacement kit in the mail from PSI. You can see how yellow the old sediment filter had gotten over the years.
Unfortunately my nitrates are still sitting at 50ppm despite doing small daily water changes. I might have to do one huge water change somehow (buy a big tub?!).