I keep reading that activated carbon will deplete the fertilizers we use. I doubt that being true, but it would be very easy to test. Just get a small tank of water, put a HOB filter on it, with activated carbon in it. Add some KNO3 and measure the NO3 with a test kit. Run the filter for a few hours and retest for NO3. Then repeat with KH2PO4, testing for PO4. It would be much harder to test the effect on the chelated micronutrients, but an iron test might work.
Has anyone done this? It would be a week of fun at the most.
Has anyone done this? It would be a week of fun at the most.