RE: Glass for Tank Top

["Eric Wahlig" <ewahlig at earthlink_net>]

In a post last week, Rachel was asking for opinions about lid construction
materials such as glass. Personally, I hate glass lids. I have broken or
chipped so many that I had to find another option. An annoying problem with
glass lids, besides the unacceptable fragility, are that they are not very
customizable. If you want the tank to be viewable from both sides then the
filtration plumbing and wiring must enter the tank at the end. Standard
glass lids are not designed for this option. Another annoyance is that the
black plastic hinge that holds the two pieces of glass together runs
parallel to the fluorescent lights and, quite simply, could not be placed
in a better location to block the light. What really got me motivated to
find a solution was when I needed to make a lid for a 6 foot long 125
gallon tank. This was an old All-Glass brand tank and had no center brace
and I could not find anyone who had the plastic bridge pieces that allow
the use of three 24 inch glass lids. I tried several options but the best
one was 8mm polycarbonate sheeting as is used in greenhouse construction.
This material is easily cut and shaped, extremely lightweight, and has 80%
light transmissivity. Best of all, its unbreakable. I am experimenting with
it now and it seems to hold up well under normal T8 lighting. The T8 lamps
are only 1/2 inch above the lid but they run very cool with an electronic
ballast. I've not yet tried it under PC fluorescent lighting. A 2 foot x 8
foot sheet cost me $20 from a local outfit that builds mini greenhouses. 
      
--- Eric