Harlock, now that you mention it, it was that thread where you discussed your experience that I was thinking about. Thanks for posting again.
Based on my limited experience with fishless cycling (one 5g no seed, 1 38g seed added) I would say that you are probably looking at 3-4 weeks for a cycle. The tank with no seed took about 4 weeks and the one that was seeded was closer to 3 weeks. Your mileage will probably vary.
One thing that I was thinking (you can try this if you feel like experimenting) was that the first stage of the fishless cycle where you add the large dose of ammonia did not seem to go faster with seed material at all. The first wave of bacteria seem to establish themselves very quickly with or without seed material. If seed material is in limited supply, and I was attempting another fishless cycle, I would start to add my seed material after the bacteria that break ammonia down into nitrites establish themselves and then add seed material once the nitrite spike begins. Or, if I had enough material, add some at the beginning and more once the nitrites appear. My reasoning is that the early lack of nitrites will starve off the bacteria that work on nitrites so the seed value of material added too soon may be diminished. Anyway, this is just something to try if you are feeling like doing some testing, I'm not sure if I am right.
To get back more in line with your question I would guess 3-4 weeks with a fishless cycle but it will be a relatively stress free 3-4 weeks (no fish in danger) and you can spend that time decorating, reading up, obtaining any necessary supplies and seeing how well your set up works.
Still king of the ambiguous post, am I. Sorry, getting a little Yoda on you, Star Wars is out soon. Anyway, I ordered from there and the batch I had was... not the best batch. My tank did cycle in two weeks without seeding, so obviously it had some viable bacteria in it. However, I did have huge ammonia and nitrite spikes especially considering I added the 90 gallon pouch to a 29 gallon tank. I still think it best to add BIO-Spira and then add ammonia, as if you were fishless cycling and take the test results. If you can get 48 hours straight with 0 ammonia and nitrites while showing some nitrates at around 10, I'd say you're good to go. Some people will get those readings after 2 days or it may take two weeks like me, or in some cases, people have simply had batches of BIO-Spira that were no good and the tank took 4-8 weeks, like a regular old cycle. So, err on the side of caution and test the BIO-Spira against ammonia, like a fishless and you're good to go.
