# Is there a glass thickness calculator that takes the Safety Factor for tempered glass into account?



## jeffkrol (Jun 5, 2013)

Most only use tempered glass for the bottom.. at best..


> "Tempered glass is too brittle for most aquariums over 60 gallons and even in 60 gallon aquariums it still should NOT be used in the bottom.
> Float glass on the other hand is much more flexible and gives into the natural bowing/flexing of an aquarium holding water (based on 35 years of aquarium repair as well as apprentice training at a leading premium aquarium builder)."


Problem is "if" you get a nick/chip in the side panel the whole thing will instantly shatter and dump..
As opposed to possibly just a crack/chip. Better odds I guess..

That's all more common usage than hard fact though.

Just make sure to float the bottom.

As to your orig question actually there is..but atm I lost it..


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## minorhero (Mar 28, 2019)

MarkFleener said:


> I want to make a 70 gallon rimless aquarium that's 36" x 18.5" x 25.5" H with a 1/2" thick bottom and I'm thinking of using tempered glass all around, low iron for the front pane and lid, but I'm wondering what the safety factor for 1/4" thick tempered glass would be in these dimensions.


My understanding is you want a tank that is 1/2" thick on the bottom but with 1/4" thick sides. This will not work in the dimensions you listed. The issue isn't with the strength of the glass but rather in the seams. The thicker the glass the stronger the seams because there is more silicone in contact with the glass. In your case the height of your tank is also a BIG problem. The higher the tank the thicker the glass needs to be. A 25.5" tank is quite high indeed. Here is an aquarium glass thickness calculator. Generally you want a safety factor of at least 3.8 with more being better (your aquarium has less of a chance of busting a seam 3 years in with a larger safety factor) 

My guess based on your other thread is you are trying to figure out how to make a low iron glass rimless aquarium on the cheap. Unfortunately this is not really possible. I did a LOT of research making my own rimless aquarium and what I found is that the cost of glass by itself was frequently more then buying a professionally built rimless aquarium. This was compounded in any aquarium that was not "nano" size. 

Anyway the long and short of it is that you would need at least 11mm thick to make an aquarium like what you are listing, since glass doesn't come in that thickness you would actually need 12mm or 1/2" thick glass all around.


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