Glass thickness

[captmicha]

One of my 55 gallons has glass that's only 1/4" thick.

I'm assuming that means I can't use it for fish?

Does anyone know at what size the glass thickness matters?

And do you have to use tempered glass or something? I've been thinking about using windows or other planes of glass I already have laying around for some of my broken tanks. And maybe for some smaller DIYs.

 

[jonclark96]

Micha:

I'm no expert, but I think that all of my 55s have glass that this thinner than 1/4", probably more like 3/16". All of mine have center braces. Maybe someone with more experience will weigh in.

I think the importance of glass thickness has a lot to do with how large the glass panel is and how often it is or isn't braced or supported. I can tell you from experience that glass will bow quite a bit if not supported. I purchased a used 55 years ago where the center brace was broken. I test filled the tank and without the brace, the tank bowed 1" at the center when full. I'm certain that the tank would have eventually failed without the center brace installed, but I replaced the top trim and the tank has been in service for 4-5 years with no issues.

With respect to tempered versus non-tempered, I don't think tempered glass is a necessity on most traditional sized smaller tanks (under 100 gallons). Manufacturers occasionally use it on tanks due to availability, I think. The biggest issue is that tempered glass cannot be drilled, so if you are looking to make a tank that you need to install a bulkhead, you shouldn't use tempered glass.

 

[AndyNarwhal]

An Aqueon 55 is 5/16" when untempered and 1/4" when tempered. Tempered glass is stronger and less expensive than the untempered glass but cannot be drilled.

The thickness of the glass is determined by the height and the length of the panel. The longer the panel the more it will bow under pressure, the taller the tank the more pressure put on the panel to cause the bow. A center brace helps strengthen the panel and reduce bowing.

Tempered glass cannot be cut so if you have glass around that is already tempered you can only make tanks that use the panel as it is. If the glass is not tempered you can score and snap it to shape.

 

[captmicha]

Thanks! I'm praying to the fish gods that both my 55's are water tight with no broken braces. And have braces...

 

[cabinetmkr39]

Tempered glass is less expensive ? Its been my experience that tempered glass is a second process after the glass is cut. That extra process is at a extra cost.

 

[AndyNarwhal]

Tempered glass is less expensive because you can use a thinner panel than the plate glass. If a tank is made with 3/16" plate glass it can also be made with 1/8" tempered glass. It's cheaper to buy 1/8" tempered glass than it is to buy 3/16" plate glass.

Also some glass only has seasonal availability. Many glass plants only run certain thicknesses certain times of the year (usually down times between when they need window glass).

But if you are comparing 3/16" tempered to 3/16" plate then yes, the tempered is more expensive.