OK, here's what we have: Pic 1 shows a close up of the fan and how the blades of a squirrel fan are much different than a computer or house fan. The blades operate like a water wheel at a mill. Pic 2 shows the fan in my hand to demonstrate just how small it is. Pic 3 shows two of the fans placed over a dollar bill (my income tax refund); I cut plastic off of the fan on the left to make it even smaller. Next two pics are of the front and back of the transformer. The 3 volt setting doesn't do anything; not enough power for the fans. Actually, I've found that the lowest 4.5 volt setting is all you really need to keep condensation off the front glass and to keep tank air circulating or refreshed (I'll explain that later). Next pic is of a circular bead storage container I got at Joann Fabrics, trimmed away the bottom and three sections of the side plastic and covered it with noseum netting to keep the flies (and frogs) out. The next two pics show the fan setting inside the circular container. The 9th. pic shows the fans setting inside of a standard pipe available at any hardware store. Pic 10 shows the hole I drilled into the top of the tank to insert the LIDDED capsule.
OK, because outside air can reduce proper tank humidity levels, I have installed the capsule in the top glass portion of the tank. With the lid on, tank air is merely recirculated, thereby leaving humidity unaffected. My tanks are connected to desktop humidifiers ($40 from Walmart), so when they are running, that's a good time to remove the capsule lid and introduce fresh outside air. THE BEST OF BOTH WORLDS!
A couple of very respected froggers sent me PMs after seeing posts on sites about these fans and expressed their opinion that the computer fan was the better choice. One frogger said that this fan does not disperse at a wide enough angle to keep the front glass clear of condensation. My tests prove otherwise. I am not about to engage in a debate over which of the two type fans is better. I am offering these fans only because they work for me and, IMO, they are the better choice. I am offering a money back guaranty; you pay return shipping is all and return the fan in the same condition as shipped. I cannot believe anyone could possibly be disappointed with these remarkable fans.
My tests: The last pic shows the fan and a small piece of paper towel dangling from a string. Since the constructive comments I received from these two members related to power and angle of wind dispersion, I tested both (even though these fans do the job in the large 20" x 30" tank 20" tall that I am presently building). The 12v setting you will never use; its simply way too powerful (and noisy IMO). However, at this setting, as far away as 12 FEET, the paper swayed in response to the breeze created!! At 9 volts, still 12 FEET. At 7.5 volts, 6 feet; at 6 and 4.5 volts at 5 feet!! The breeze from the fan dispersed at a wide 40-45 degree angle in as little distance as 8 inches.
Another observation made by the respected frogger (and please know that I am using this characterization very sincerely and respectfully, as this person is most definitely a very respected frogger and I personally have great respect for him), which I agree, is that "It's not about feeling the air, or seeing leaf motion that is really that important. It is about the overall circulation." These fans provide all the "overall circulation" you will ever need.
Finally, no, I am not in the business of selling frog fans. As I said, I put these together and they simply worked. I "hired" my son to build 20 of these (40 fans total; 2 fans per set) and just thought I'd share these great little fans with others and, at the same time, provide young Michael with a little extra spending money. I have 10 fans left. I have not gotten a single one back and have received nothing but praise from seven of those ten who have purchased them. All I can tell you is the truth.
I can run these fans 24 hours a day at the lowest setting. When I come home, I remove the lid for 20 minutes just to introduce some fresh air into the tank. The remaining 23 hours and 40 minutes, the fans run QUIETLY to recirculate the air within the tank. If everyone ends up happy with the lowest setting, then I will consider selling these fans with a one-setting transformer, which I can buy cheaper than the multi-power setting ones---then pass the savings on to you. Ed