itafx said:I've purchased several Marineland hoods that include a combination of opaque and clear plastic materials of some kind and they hold their shape just fine. I was looking for a cheaper and more versatile DIY solution, though.
Glass is hard to cut properly, easy to cut yourself on the sharp edges, and easy to break unintentionally.
Ziggy953 said:Are you trying to seal the top of the tank because of jumping fish or just because you want to? Either way have a look at eggcrate...the material used in floresent light fixtures in office buildings.....also seen in tanks at LFS to hold coral frags ect...it's much cheaper then 1/4 acrylic and will not sag like the acrylic will also it will allow the O2 exchange needed....HTH
FMJnaX said:itafx said:You could look for cell-cast acrylic
Cell-cast sounds interesting. Do you know if it cuts easily and neatly on a table saw like extruded acrylic does?
Here's a link to a DIY cast-acrylic refugium. It appears to have some good ideas.
http://saltaquarium.about.com/library/blank/bl_diyacrylicrefugium.htm
Sicklid said:I work in the sign industry and I cut lexan, bi-carbonate, plexi and acrylic all day long, and none of them will hold their shape on top of a tank unless you used a minimum of 1 inch thick, so do yourself a favor and get an 1/8 inch glass top from a glass shop and get plastic hinges. I once tried half inch acrylic and it bowed the first day. The plastics that marineland uses is not plexiglass, it is more of a clear ABS or pvc. But even then, they are just used in small sections for light bulb windows on black ABS plastic hoods, not entire tank top spans. For that they sell kits made from glass with the plastic hinges as I described.
What you say makes sense, but then what do the acrylic aquarium manufacturers use for their tanks so it doesn't warp?