you may find a pvc bushing that will bring you down to that size or check hobby lobby for the right size tubesee how the glass is much smallet in diameter? what to do? if you look at the link you posted, they guy has the larger end of the pvc connected to tube. wtf?
dystppia, if you look at your first and last pic you can see a gap between the glass and pvc. how is it attached? and is it airtight? lemme know because if you look at my pic above its the same.
Like lil babiesI can't take the glass out to show you right now 'cause they just went to sleep.