Fluorescents 2' above tank - will this work?

[Blinky]

Hi all,
This is technically an equipment question, but it's directly related to my plants so I thought it best to post here.
I've just finished cycling/setting up a little tank in the bedroom, and thought that the old 18" fluorescent fixture I had lying around would provide enough light - a 15W bulb on a 10g tank, 1.5WPG. Well, even if it's enough for the plants to live with (and at this point I'm not sure it is), I'm just not happy about it.
Today I went to Home Depot and found simple fixtures that are 24" long, with 18W T8 bulbs. They're not built like an aquarium light, they're meant to be fixed to a wall/ceiling, so I'm thinking that I'll mount them on the ceiling above the tank.
Here's what I'm wondering:
The tank is on top of a cabinet, at standing eye level. The top of the tank is about 24" from the ceiling. Will 36W of light mounted 2' above the tank give enough light for a 10g (planted with crypts and some water sprite)? I know that the depth of water the light travels through really affects how much actual light the plants get, does air space have a similar effect?
I can leave the old 15W light on as well, though it will block a lot of the light from the ceiling by covering most of the glass on the top of the tank.
Thoughts and opinions would be appreciated :)

[beviking]

Can you suspend the light so it hangs closer? It's the light scattering everywhere else between the light and tank and not getting into the tank that is the problem here. Light travels much farther through air than water. I don't know if it would work...maybe? I know that isn't much help.

[geoffgarcia]

I would recommend against rigging anything like this.
no offense, but it just sounds ghetto...I've been there and tried all the ghetto rigs you can imagine

suspending lights should be restricted to metal halide pendants and even then only in extreme cases. Lights belong in canopies IMHO.

While the light will work find and have a great impact on your tank, I think that the negatives of the extra light washing over your room and the unsightly look are major cons. Spend a bit more and get a proper fixture.

[Blinky]

:laugh:
Thanks for the giggle - I'm decidedly against my fishtanks being 'ghetto' in any way (other than my DIY CO2, nothing I can do there for now ;))
I've actually put one of the strips (and they're nice, contained looking little units, meant for under cupboards in kitchens and such, not just bare bulbs like shoplights) behind each tank - they're on timers, set to go on and off one hour before and one hour after the tank lights to create 'wake up' and 'wind down' times each day (and if they provide a bit of extra light while they're on during the day, great!). I've been using an old strip on shelf brackets (yup, little ghetto, glad it's gone) behind my 45g to do this since I got the CF fixture and the fish seem to appreciate not being shocked into/out of total darkness.
Still doesn't solve the immediate lack of light in the 10g, but I'm working on it and so far the plants aren't complaining ;)