Hi Bob and Welcome to TFF!
Congrats on the nice-sized 37G tank! You are correct that the bottled bacteria probably won't do any good. You have stumbled on the right place!
Have a read of our Beginners Resource Center, specifically, read the Nitrogen Cycle and the Fishless Cycle articles and look for a general startup article by Miss Wiggle.
You are also correct that if you could find a hobbyist, friend or fish store that would donate or sell some "mature media" (sponge, ceramic gravel, floss or other biomedia from a filter that has been running a long time) it would likely speed up your fishless cycle.
You say that you want to cycle as fast as possible but I have a different perspective on this. The tropical fish hobby is very different from most other things is modern life (somewhat thankfully!) It is all about slowing way down and "puttering" and enjoying things and relaxing. The ultimate goal is somewhat familiar even to those without tanks yet, its that moment some night when you stare into your underwater world and just get lost in the beauty of it. I would propose that the journey to that point can also be enjoyed and can enhance that moment if one has put more into the background learning.
The two specific species of bacteria (Nitrosomonas spp. and Nitrospira spp.) that we need to grow inside our filters to create a working biofilter are notoriously slow and picky to grow. They, all by themselves and despite all our frantic efforts, are the limiting factor in the filter cycling process. Its just a fairly normal fact that there are not many of these bacteria that have managed to stay alive in the typical tap water system and it takes billions of them to make a good filter. So the process of growing them (-without- mature media helping the start, and sometimes even -with-) often takes between 3 weeks (that's rare and a bit chancy anyway) and a little over 2 months and it varies wildly for different individuals. BUT, its worth it! Its a core aspect of the hobby and it will give you some hands-on learning that will be forever valuable to you later.
It also turns out that the 2 months often spent fishless cycling the tank will feel quite short later as the months and years of tank maintenance with fish roll on and on. That little beginning period will carry a wealth of learning. And its a perfect period to learn the somewhat difficult process of creating stocking plans and learning other beginner tidbits.
Anyway, if you happen back on here I hope you'll take up some questions with the members!
~~waterdrop~~
