I finally managed to finish a long-time project of mine. Since I live in a loft apartment which becomes quite hot (30-35°C) during the sommer months (cheers to the non-existant roof insulation *sigh*) my loach community tank really needed some way to be cooled down a bit.
A professional compressor cooler was out of question (much too expensive, draws a lot of power, would heat up my room even more) so the only thing left was to install some fans in the aquarium cover that could blow on the water surface, hence cooling the water by evaporation.
Step #1: A black 3 mm board made out of PVC hard foam.

Step #2: Board cut to the right size, holes for the fans, screws, cable and a handle added.

Step #3: Bottom side, 2x 80 mm YS-Tech FD 128025LB (2A3) fans from a PC-Tuning shop added (with grills on both sides for the extra-curious fish). Those are rated 12V / 2000 rpm / 51 m³/h. I run them at 9V though so they turn slower and even more quietly.

Step #4: Bottom side, while I was at it I thought I could also add a moon light to my tank so the changes in lighting would be less 'brutal'. Again from a PC-Tuning shop, a 30 mm blue cold cathode fluorescent light (CCFL) with some aluminum tape for better reflection. CCFL is glued to the cover (bad idea) and the cables are fixed with adhesive tape (even worse idea).

Top side.

Step #4 .. revisited. Now that I think about it again I have no idea why I thought any kind of conventional glues would withstand 100% humidity for more than a minute .. because they don't.


Again .. top side. Connectors to the power supply hot-glued to the cover.

The original "Juwel" cover.

My creation.


Finished! The blue box is the inverter needed for the CCFL (those run at 680V


And now the best part .. the cooling really works! The fans cool down the tank for about 1°C in just 2 hours so it's really easy for me now to keep the water temperature below 30°C even on the hottest days of the summer. The blue moonlight looks absolutely awesome and my fish seem to like it, too.

-Connor