I set-up a tank just like what you described about 6 months ago. (high tech 5.5 gallon shrimp tank - co2, EI, good light)
First, the silicone. I bought some silicone-specific remover at Home Depot, and rubbed that on, then spent 4 hours with a razor blade scraping. Lots of patience and elbow grease, and you'll get it all.
Second, the light. I originally had one of the 27 watt home depot desk lights over the tank, but wasn't happy with the coverage. I always really liked
waterfaller's tanks, and i noticed she had a
2x24watt T5HO Current Nova Extreme spanned over 2 of her cubes, and i figured while it may overhang a little, it would work well for me.
It did. After being overcome by thread algae, I ended up pulling both bulbs out, and putting a single
Giesemann Midday bulb in. The results are awesome, tomorrow I'll put up some pictures of the tank. Lots of high-light plants growing well, no more algae, with RCS and amanos as occupants.
Looking back, my lighting solution was pretty expensive for a small tank - close to $100, all told. but the results are amazing, and the single giesemann bulb keeps algae away and plants growing great.
