Hi,
can anyone tell me if putting a 40watt blue flouro bulb in the tank light will dim the light enough that you can still watch your fish at night without disturbing them?
thanks.

IN the tank? Are they underwater lights? If they are I need to know how they work out for you. If you mean on top of the tank I think it would look wonderful and they fish would probably still be able to sleep well.

Ya i have a blue bulb aswell (Moonlight), I keep it on sometimes at night, it doesn't really bother the fish, the light isnt too bright.

I don't know about those bulbs, but I use LED spots which i places above the outlet of my airstones.I put Blue lenses of pondlights under the LEDs.
It creates a very nice "moonlight moving on the gravel-effect".
In addition i mounted 2 refridgerator lightbulbs on the top of the tank, partly covered with Alu-foil.
I can adjust the light however I want.
I even leave the bulbs on at night in the winter for some addition heating.

I orderer some Blue Xmas LEDs on a string this week, and plan to try those.
I saw some pics on MFK at it looks awesome.
Yeah. I like my tank best at night, thats when the monsters come out!!!

I'd love to see pics Noddy. It sounds great.

the only draw back to led lighting in the tank i found was the spot effect from each individual bulb. for this reason when i built my moonlighting i used cold cathode light bars(the same as used in pc lighting) . i found this gave a more even distribution of the light in the tank.

jsut my opinion

True!
Thats why i placed them over my airstones and use lenses.
Got one still in spotlight-mode, pointed into the main plecocave.
They don't mind and I can see very clearly when the action starts!!

Will post pics when I got them!

looking forward to the pics....

mine is a 40w blue in my post titled "star trek lighting" in this section ...and it was far to bright for a tank 34" deep ..so i had to dim it down with a homemade diffuser (black plastic)

Checked that thread out, and YES, that's what I like.
Insomnia was a nasty thing before I got moonlightíng in my tank.
Nowadays when I cant sleep I allways know my fish are awake as well!!!