Orchid air circulation fan
 

I recently bought a 75 gallon tank for orchids and I need to know what is the best cheapest and easiest to set up fan to supply good air circulation for my orchids. I plan to mount the fan internally for air movement. I see a lot about wiring computer fans but it confuses me I am not very good with Electric work. If you can recommend something and explain in detailed steps on how to wire it I would greatly appreciate it.

First, keep in mind you are looking for air movement, not a breeze, per se. The idea is to eliminate stagnant pockets.

I don't know why folks buy computer fans then mess with a power source too. Radio Shack used to carry 110v versions, and I see them on Amazon now.

You need:
Fan (1-4) ea
Lepa 120mm x 25mm 70D Cooling Fan - 12V / 7V / 5V (LP70D12R) - FrozenCPU.com

Barrier Terminal Blocks 1ea
39100-1002 Molex | Mouser
Or
Wire Connector 12-Position Barrier Terminal Block 10A - CA$1.75
AC / DC Power Supply (1-4) ea, but you can connect 2 fans in parallel.
Amazon.com: New Genuine D-Link 5V 1A AC / DC Power Supply Adapter Model Number: AMS47-0501000FU: Electronics

Flush Cutting Pliers

https://www.theelectricaltoolstore.c...ers-p-357.html
Or Ordinary kitchen knife
And a small (-) screwdriver

You don’t need wind storm, the fans runs at low speed without noise.
You can buy power adaptors (charger) from 110V AC to (5-10) V DC (200mA-2A) from Salvation Army thrift store for $3.
And attention; polarity, if the fan will not runs just swaps the lines in connector.

Sometimes I really feel like an idiot. I've been building my own computers since my first Altair kit in 1976, so when it came time to provide air circulation in my Exo Terra tanks, I naturally thought of using old pc cooling fans lying around the house and connected them to old cellphone power supplies. As I sat there stripping very thin wires and enjoying the solder rosin vapours, I thought, "Sure would be nice to be able to just buy some of these fans already wired with a standard house plug for power." But did I actually bother to LOOK for such a thing? LOL, nope. Thanks for posting. :)

I did find something, however, that was easy and has worked out very well: a Silenx 4 fan, variable speed fan controller. Got it from Amazon at Amazon.com: Silenx IXAFCEX Four Channel External Fan Controlle: Computers & Accessories. It's basically a power strip for pc fans with four pc fan power connectors that you can just plug into the wall.

Works well, it can run four pc fans and you can control each fan's rpm with adjustable knobs. Only thing I don't like about it are the bright and annoying blue LEDs, which I cover with electrical tape.

Another suggestion...

There are very inexpensive external cooling fans of various styles for laptop computers that plug into USB port for power. Also personal desktop fans that use USB. And AC power adapters with USB output for charging tablets and phones. No assembly beyond plugging this into that, standard hardware that can be combined in different ways, no AC line voltage into the wet environment, timers available if you don't want constant circulation, and all for a few dollars.

Would these fans work for my 75 gallon acinfinity.com/speed-control-fans/ranged-dual-kits/ac-infinity-speed-control-fan-kit-ranged-dual-80mm/

Anyhow for a PC variable speed controller you need a 12V power supply, plus iron solder, I think is better a Universal AC to DC Converter.
Amazon.com: Seven Star 1.5V, 3V, 4.5V, 6V, 7.5V, 9V, 12V DC, 500mA Regulated Universal AC to DC Converter with Multiple Connector Ends: Electronics

Yes its 0K, but maybe you need 4 fans.