Biocube retro, rewire fan?

[Simulated Fish]

I have the retrofit in my little 8g biocube and due to the channels and moon light the fan is at an "always on" state. Now this was fine when before when the tank was not right next to my face  but know that I will be setting it up on my work desk it needs to be controlled. I don't want to damage the lights electronics and I am not sure exactly what parts I would need.

 

I was thinking 2 options;

1) insert a switch between the fan and the electronics, a simple on off switch would be easier but one I could control, like a rotary dial switch would be best. Is that possible?

 

2) Cut wires and attach fan to a separate power source with a rotary dial switch. That way I can manually adjust the fan speed. I'd hate to have a separate power cord so this is not my favorite

 

3) ???? Maybe you guys have an idea?

 

Thanks in advance guys!

 

[Water Dog]

Do you have any open channels available on your driver board?  If so, you could get a Meanwell SCW fan driver to control your fan via the Bluefish mini.

 

http://www.rapidled.com/mean-well-scw05b-12/

 

http://www.rapidled.com/mean-well-scw05c-12/

 

Not sure exactly which one would work...  perhaps someone smarter than me could answer that.

[Simulated Fish]

@Water Dog there are not any free spots, that's why Dave hard wired it unfortunately.

[Water Dog]

Oh, okay.  Then go with option 2. 

 

http://www.rapidled.com/fan-speed-controller/

 

http://www.rapidled.com/12v-ac-adapter/

 

You may have to cut off the speed control connector as it has a 3 wire connector and use heat shrink butt connectors to connect the red and black wires of Dave's 2 wire fan to the speed controller disregarding the yellow wire.  Or replace Dave's fan with one of the 60mm fans that RapidLED sells that comes with the 3 wire connector.

 

 

 

[Simulated Fish]

 

So I did a bit more research and found the easiest and simple set up was to place a rheostat in line with the power wire. I used a 25 ohm 3w rheostat. Cut the power line going from the power source to the fan. Wired the rheostat in-between, cleaned it up with some shrink sleeve and done!

 

I used a simple screw tightened control knob on the rheostat to make it pretty. The mounting is through the biocube's existing rubber toggle switch cut out, just poked a hole in the rubber and removed one of the toggles. I was going to use one of the non in use power cable holes on the rear to mount. It was a perfect fit but it was outside of the splash guard and I was worried about salt creep and splashing shorting the lights out. This isn't as pretty but it is safe and functionality is great.

 

The fan can be reduced to 25% and is SO MUCH QUIETER! Can't wait to get this tank wet again.

 

Also for any one in the future brought here by Google here is a photo of the parts and placement.