How Do I Tell If My Aquarium Is Glass Or Acrylic?

Hello. I have two tanks that I have bought off Craigslist, so I do not know what they are made of. Any ways to tell what they are made of would be appreciated. Thank you!

 

acrylic aquariums are basically plastic. usually doesn't have any of that black bracing or anything. the tank is one single piece.
glass tanks are made up of glass panes siliconed together. Usually has black or brown bracing around and across the top.

 

can you post a picture? That would help identity

 

If it is glass it is going to have silicone on the sides...if acrylic then it won't have that.

 

acrylic aquariums are basically plastic. usually doesn't have any of that black bracing or anything. the tank is one single piece.
glass tanks are made up of glass panes siliconed together. Usually has black or brown bracing around and across the top.

Thank You!

 

If it is glass it is going to have silicone on the sides...if acrylic then it won't have that.

Thank You!

 

Can also tell by tapping it with your nail. Glass will make... well a more metallic (?) sound in comparison to arcylic - tends to be more dull..

Basically if you were to tap a wine glass and a plastic tupperware contain you will hear the difference.