Seachem makes a great product. For it to work properly, it has been my experience, you need to put it in a reactor and run a low volume flow through it. I know you dont want to hear it but "dilution is the solution to pollution" in the case of nitrate. If water use due to water changes is a concern, I feel better draining my 150g per week onto my lawn. I know I will probably step on toes saying that Pythons and similar devices waste a ton of water, and I know there is the convenience factor, but Pythons and similar devices waste a ton of water.
Anyway, a nitrate reductor tower is a great device that really works and I have even seen some DIY creations online. Just know that a reductor tower needs the right chemical components also and arent as cheap to operate as they are made out to be. The ones that use a media, use media. The one that require intense light, require intense light(electricity). The Seachem media isnt cheap and if you just put it in a media bag, throw it in a sump or put it in a canister etc, I dont think you are using the media to its fullest potential, i.e reactor tower. If you can build one, go for it. I think in the long run, water changes more than 50% weekly still is a cheaper way of reducing nitrate. A constant water change system is definitely worth looking into and is almost a 100% guaranty of 100% nitrate removal.
Just my 2.