go for it, I have on in my 8 gallon it's awesome, it's way better than just a direct flow going into the glass, as far as it fitting, it most likely will. It comes with a couple different size fittings that you'll be able to make work.
yeah it will fit, i had it going on mine for a little while. I ended up not using it because water was splashing on the light hood. I might give it another shot sometime.
