FishProfiles.com Message Forums

i was looking at the tank dimension and saw the column for 'tempered bottom'. i'm guessing the X means not tempered. what does that mean?

Tempered means that the glass will shatter into many small pieces, much like an automobile windshield. It is also a bit stronger than untempered glass. It is a safety feature in windows to prevent serious cuts if broken.

---

Water, taken in moderation, cannot hurt anybody. -- Mark Twain

Tempering is a process to harden materials. As OldTimer has said, this normally makes it more brittle under impact, but much stronger under continuous load - such as 300kg of water pressing on it (for a 300L tank). Water weighs about 1kg/L... so think about that the next time you want the 'cheap' big tank or stand!

The Auto glass... i'm pretty sure it's internationally been laminated since about 1965. They use toughened glass for side windows, which is a little different to tempered, but reacts the same under impact. I'm pretty sure the lawyers in the U.S are the reason laminated windsheilds became the norm.