I did a bunch of reading last night about plants that absorb nitrates. Towards the end of my search, I came across this Plants As Filters
. If you scroll all the way to the bottom there is mention of how terrestrial plants absorb phosphates while aquatic plants absorb nitrates.
In the response, Tom mentions using a peace lily, but I didn't want to do that or spend cash on a plant. Instead I have a philodendron that was in need of trimming, so I thought I'd give that a try.
The plant pictured is one of many I have around the house. I've had the mother plant for several years and since I don't use pesticides or chemical ferts, there is no worries about putting weird things in my tank. The plant itself is toxic to cats and dogs, however, where the filter will be going neither my cat or dog have access to it, so I'm not concerned about that either.
I typically root philodendron clippings with growth hormones which works well, but since I've never tried it just using water, I'm not sure how long it will take before I see roots. When I plant them in dirt I don't look for roots. Instead I gently tug on the stems to see if I get any resistance.
From what I've read, it can take a week to 10 days. Wednesday when I do a water change, I'll swap out the tap water for tank water to see if that speeds up the process. When I start seeing roots, I'll order a filter.