would a very small low power white led unit cause algae if used as moonlights?

You left out information.
How small is small ?
Are you talking one or a few ?
How bright is one or more than one ?

Hi jbrady33,

If the aquarium is located where it receives ambient room light I would be more inclined to suspect the longer days we have just experienced; June 21st has the most daylight hours every year.

Haven't tried anything yet, still buying equipment.

Only ask as many of the LED fixtures come with blue moon lights, just looks odd. Was wondering if a very dim white led (maybe a little clip-on or something) could be on all night instead of the blue ones.

I have a small led, that came off of a Current Satalite 40 watt pc fixture. I mounted it down behind the aquarium. The light shines up and reflects off of the main light reflector. It throws just enough light in the aquarium so it is not completely dark.