Review on Highly Efficient Seachem Purigen for Freshwater & Saltwater Filtration by Andrea Smith

I bought Purigen to help my 29 gallon reef tank which is regularly tested for 40ppm nitrates. Putting it in my filter my next test fell to about a 5 and I was hooked. Then the nitrates were back to 40 the next week. I tried different Purigen packs and even refilled the Purigen pack thoroughly. I only gave Purigen 90 days of work. My nitrates never went below 40. I ended up solving my problem by stopping Purigen and doing two 20% water changes a week instead of one. Now my nitrates are almost zero. From all the good reviews, I can see that Purigen really works for some people. I suspect my high nitrate levels were caused by something Purigen cannot neutralize. As this is an expensive medium, I would appreciate a more detailed explanation on the packaging of how Purigen works and what are the main causes Purigen aims to address.