I have discovered a simpler way to do the cool tubes. I will get pics and a tutorial up when I can afford batteries.
I tried the tube guard approach earlier this year and rejected it.
You can purchase clear 2" rigid tubing used in central vac installations. The elbows and connectors for central vac tubing are much easier to work with and form a tight seal. The multiple connector options also allow for more varied manifold style connections for air flow controls, too.
Central vac tubing is a little more $ than the tube guards, but still very inexpensive.
sorry no pics still. Im laid off and broke. Better to have weed and be broke than to have money and no weed I guess...