Pleccy is right, a cycle in 6 hours may well work in a few cases, but such methods will always be frought with dangers, and are certainly not for beginners. ive been keeping fish for 12 years, and even i wouldnt risk it! the thing you have to remember is that what makes aquariums work (or the filters at least) is bacteria! and bacteria has a growth rate, which cannot usually be sped up to that extent, not when it would normally take 6 weeks under average conditions! im sorry, but basic biology and chemistry is against you. i dont know what you did, but i honestly wouldnt trust it in the long run.