I think it's an aqua tech or something cheap like that. I'm using HOB's I had laying around. I filled the chamber about 3/4 full with gravel, put the plant in and buried the roots, and then topped it off with gravel to the top. Just make sure you don't get gravel in the middle part where the pump impeller is. It makes a horrible grinding noise and will probably ruin the pump. I noticed on your earlier post you thought about using some sort of container for this. I think you need water flow in and out for this to be effective.
I also use Pothos for my tank. Am not so sure about how much nitrate is sucking up from my tank. Didnt reply do much testing. Ill give you guys some pic's once am home!
I want to do this but i only have 17" from my sump to the bottom of my stand. I would have to constantly trim the plants if they grow fast. would the plant filter nitrates at a high rate if its constantly being trimmed? Just wondering how the set up would look under the stand.