Regenerating Pura NitrateLock?

[Kengar]

I use Pura Nitrate Lock (see here (http://www.aquariumguys.com/pura-nitratelock.html) ) and have regenerated it a couple times according to the instrctions. However, I've never really monitored nitrates before/after to see whether regeneration does, in fact, work. Does anyone have anything to say one way or the other in this regard?

Thanks.