Here's mine. Top Fathom 200 with dual Kent venturi valves and a nifty new bubble trap. I have another bubble trap if anyone's interested. I may put it on Ebay in the next few days.
I have not heard of "greased" CO2 for paintball, but in Airsoft we use this "Green" gas. It has silicone in it to keep the internals from locking up since the rate of fire is so high. Greased gas is just CO2 with silicone in it. So no worries. And trust me, for the price, no one is going to...
Just fill the tube with water. Put pieces of plastic wrap over both ends. Stick it in the overflow box and pull the plastic off. I have big hands and have no problem with this method.
Don't make it 12 inches tall. It looks funny when it's that high. I had 2 250 Watt Iwasaki's over my 120 with only 7 inches of clearance with fans and it was fine. If you have splashy returns just router notches and throw a piece of picture glass in there.
I found a mogul to medium adaptor that should allow us to run an Iwasaki 150 on a 175 ballast. It's brighter, but I don't think it will shorten the life of the bulb. :D
I use this in my refugium and it works great. I did have to super glue the airline to the nozzle to keep it from blowing off but that was no big deal. Now if I could just keep the cardinals away from the overflow long enough for the inverts to capture some of the shrimp. :x