BIO-Spira is great. I've always been suspicious of stuff claiming to speed up the cycle, but after seeing the great reviews this has gotten (if properly handled--ie. refrigerated) in other forums, I decided to risk it.
Skip the following paragragh if you aren't interested in detailed ammonia and nitrite readings
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I had a newly set up 90g that had a few valisneria in it. They had died back a little, but seemed to be recovering. Even so, I had something between .25 and .50 ppm ammonia in the tank before I added the fish. Looking back, I probably should have done a water change before adding the fish, but really didn't have time that day. I added 12 cyp. leptosoma, and 8 n. brichardi, plus the shaken 3oz. packet of BIO-Spira (enough for a 90g) last Wednesday afternoon (the 5th) --also added the 2 java fern and 1 anubias nana I bought with the fish (from Ned's, of course!). The next day I found just over .5 ppm Ammonia, no discernable nitrite. Friday the ammonia started to go down. I measured between .25 and .5 again. There was the barest hint of nitrite that I could see. On Saturday, I measured something between .25 and .5 ppm ammonia again. Nitrite measured just under .25 ppm. Sunday: Ammonia was down under .25ppm, but not zero. Nitrite was about .50 ppm. Monday, ammonia was a zero, and nitrite was just above .25ppm. As of Tuesday evening, the tank is fully cycled--both ammonia and nitrite were zero--it might have been that way in the morning, but I didn't have time to test the water.
The water is very clear now, after being slightly cloudy during the last week. I guess because the bacteria was still settling in the filter and tank furnishings. To have a tank cycle in less than a week is amazing. And while no amount of ammonia or nitrite is good for the fish, the levels stayed very low. I will always use it whenever I set up a tank. Ned's Fish Factory should DEFINITELY carry it!
They claim that even if it isn't refrigerated, it still is somewhat effective--the product life just shortens considerably. Personally, I wouldn't use it unless I knew that it had been kept cold the entire time. I think Marineland requires dealers to have it refrigerated, and they only sell it directly to eliminate the possibility of having a middleman mishandle it.