[jbjints]

I just called a glass place looking for prices on acrylic. The salesperson tells me that acrylic is a brand name and that plexiglass is the same thing. She quoted me a price of $8.00/sq. foot for 1/4 inch and $6.00 a square foot for 1/8 inch. I am looking to start building my 10 gallon sump tonight, I have a 10 gallon tank that I bought the other day that I will be using as the base for my sump. Is this what I need or is the salesperson wrong?

[Reefland]

Your placing the acrylic/plexiglass in the 10gal tank for baffles right? If so, regardless of which is correct either would be fine; go with the 1/4" as the 1/8" will be too thin and bow on you. To your question though, I think people interpret this differently and I am not exactly sure which is correct. When I think of plexiglass, I think of safety glass that may be used on a storm door to prevent injuries if someone was to run through it. Plexiglass usually has a blue film paper on it to prevent it from being scratched before used, acrylic has a brown paper.

I know those aren't very definative but my belief and thoughts.

[Reefland]

Well here we go, I just found this in the similar threads after I posted:
Can plexiglass be glued to Acrylic?

[Tervill]

I used to work at a local plastics shop on weekends while I was attending college. Plexiglass is a form of acrylic. It is much more flexible and break-resistant than regular acrylic. For example, NBA backboards are made of plexiglass, the back wall in a racketball court is plexiglass. Regular acrylic is a lot more brittle and breaks and scratches very easily. Plexiglass usualy comes wrapped in white plastic and regular acrylic comes wrapped in blue plastic. This is how it is way up here in Canada anyway. Just some food for thought!

[hydrosight]

"
Plexiglas® is a trade name for Acrylic Glass and was first sold by Röhm & Haas in 1933. The trademark is registered by Degussa with exception to North and South America, where this acrylic glass is called Acrylite®.
"
So in general Plexiglas is a registered trade name for a certain acrylic manufacturer. Plexiglas does vary in UV resistancy, clearity and so on, with Plexiglas, you know what you get. Find more details on HydroSight Corp. acrylic glass underwater viewing panels for aquarium and architecture