Hi everybody,
I use GU10 LEDs to illuminate my small Tanks. For the bigger ones I use T5 Tubes. The main advantage of GU10 is the lower build heights. For Cubes I use Philips LEDs like those here: http://www.p4c.philips.com/cgi-bin/dcbint/cpindex.pl?slg=en&scy=tr&ctn=872790091824300
But the Light is very warm, which is no Problem in blackwater tanks.
In really small tanks I use 1,5W 4200K LEDs with GU10 Socket like those on the Picture. They are cheap (€2,50) and fit the needs of 12-30l Tanks…
Greetings
Oliver