Review on Boyd Enterprises ABE16743 Chemipure 11 74 Ounce by Autumn Feudner

I bought 3 of these because for some reason my nitrates never seem to go down and I've been told they are great at lowering nitrates. Maybe they are but I'm wondering if what I got was needed because if you look at the picture all 3 have some kind of weird condensation inside. Why can there be moisture in them? I took out two of these and they were wet/damp. I rinsed them well and almost nothing came off them as if they had already been washed and/or used. However, I placed them in my aquarium as instructed, one in each filter compartment, and after more than a week the nitrates were unchanged. All 3 of them I received had condensation. So I went to the local fish store and found the same product. They contain no condensation. I replaced the ones from this seller with these and within 24 hours the nitrates were already down 10 parts per million. I have one left from this seller that I haven't opened (the one in the photo). I think it's better to just throw it away and not trust it than to ask the seller to return the money. It's just really weird and I've been getting more and more frustrated with shopping at Revain lately.