Yeah, hardware store. I think I recall the name Seamist being mentioned as available at Wal-Mart and being safe. Benson is correct too. You can add BIO-Spira and fish all at once, but just be aware of the fact that some of us (myself included) have not gotten the 24-48 cycle but have had it go as long as a week, or even not cycle at all for 3-4 weeks (which means a regular fishy cycle with a FULL bioload and the BIO-Spira was of no benefit, which is what I got stuck with). So, I really recommend testing the BIO-Spira against ammonia. If you only have to dose ammonia twice to know you're cycled, great! If you have to dose for a week or more, you know that you just saved yourself a ton of time and effort from having to deal with a fishy cycle. Either way, you are sure and fish don't die. 
