Planted Tank Guru
Join Date: Apr 2011
Location: Hamilton, Ontario, Canada
I used a old PC power supply. You can make them always run by jumping the green wire with any black wire so they don't need to be hooked up to a PC to run. Then I use a timer to power the fans on and off throughout the day. I went to the dollar store and bought some telephone extensions and used that for my wiring to wire them further away from the power supply and a $1 for 50 feet of wire works. They usually have 4 wires, I doubled them up to help with the voltage travelling across.
Here's a little blurb though about getting any old 12v power adapter from an old cell phone or router or something you had laying around the house. Those adapter are whats known as a unregulated power supply. If they say firstname.lastname@example.orgA on them, it means they will put out 12v at exactly 2.1A draw on them. If you test any of them with a multimeter with no power load, you will find they are usually 14-19V without any power on them. So if you use one rated at 2.1A and your fan only draws 500mA, it may be supplying the fan with 14V instead of 12V which can result in the fan burning out faster, burning up, etc. That's why I went with a PC power supply. They put out 12V, 5V, etc at a steady voltage regardless of the draw on them. Just a little FYI since I see lots of people recommend using any old wall wart adapter and they understand how an unregulated power supply works. You can also get an old wall wart and 12V 7812 regulator and wire it in yourself, but if you're that good with electronics, a few diodes and caps and you can build your own AC-DC rectifier bridge and make your own power supply. lol.
The small 120AC - 12V molex adapters work well as they are regulated inside to keep a steady voltage to a hard drive is what they usually are used to power.
Cost vs time vs parts comes down to what you have available and how good you are at wiring, etc. I run an electronic repair shop, so I have lots of extra PC fans and XBox 360 fans laying around and PSU's from old PC's, so it cost me nothing to do this except a timer and some dollar store phone extensions.
20g platy, , 2 x 10g shrimp, 3 x 20g shrimp, 7.5g shrimp and 1 great dane/mastiff puppy.
Sump Pimp #2
My Tanks and my shrimps