I just recently set-up a 40g acrylic tank. I planned from the very beginning for this to be an Afican cichlid tank, specifically Lake Malawi and its various inhabitants. I filled the bottom with crushed coral and used about 25 lbs. of lace rock for decoration. All in one day, I placed about 10 africans in there, 5 are about full grown, and 5 are juvenilles, along with some Bio-Spira. The filter was brand new (AquaClear 500), just got it in the mail the same day. I didn't use any media from an established tank, started from scratch. Amonia is at 2 ppm. The next day, the fish seemed fine, I tested the amonia and got .25 ppm. A drop of almost 1.75 ppm overnight! This goes to show that the nitrifying bacteria is working! I can't believe Bio-Spria actually works. If you definetly have to set-up a tank asap, I strongly recommend this product, although its a big expensive ($20 for 3 oz., good for 90g) its worth every single penny! No more waiting weeks to cycle the tank, this takes mere days!