Am I going to have 210 gallons of broken glass?

[nmoran]

I'm building a 210 gallon tank. I've already build the wet/dry and bought the skimmer. My question is; if you know, if I'm not going higher then 24 in. Will 1/2 glass work. I don't won't to spend $400 and when I put water in it have it bust. It's also 6ft long and 3ft wide. That shouldn't matter should it.

 

[underthesea]

If I was to build a tank of that size I would go with 3/4" or 1" thick glass. $400 is not much when you concider what it would cost if you went and bought a manufactured glass aquarium. Better to be same then sorry.

 

[drkegel]

Use glass that is AT LEAST 3/4" thick. There is NO WAY 1/2" glass will support that weight load. To be clear, the amount of force exerted on the walls of an aquarium is the same, no matter what the shape of it is. You still have 200 gallons weight and force wise to deal with, regardless of how tall/wide/long it is. 200 gal is 200 gal. It kind of reminds me of the old engineering joke, what weighs more, a pound of water or a pound of ice. A pound is a pound is a pound. (Unless your weighing gold, but that's another story.)
Is the tank being built into a wall? Or is it freestanding? If it's going into a wall, you might get away with thinner glass on the sides that have supports behind them.
If it were me, I'd use tempered glass too.
IMO, The most critical part of any aquarium, structurally, is the quality of the joints, where the two pieces of glass meet. Each of those joints is going to be the weakest part, structurally, and where an aquarium is most likely to fail, given there are no cracks in the glass.
HTH. I can do a stress load analysis for you, just drop me an email.

 

[johnny1]

I have a 220 gallon perfecto with 1/2 glass !!! It is like 400 pounds empty and has a lifetime warranty!!!My tank is 30 in tall 72 in long by 24 in

 

[drkegel]

1/2"?? Are you sure it's not 5/8"? I did a load anlysis last night, and to my surprise, 5/8" is what came out.
Apologies for not doing the analysis first!
Unless you have experience in glass working and know how to make good corner bonds, I wouldn't risk it on the 1/2". I'd go with 5/8". Good Luck.

 

[diatom]

Dr~
I haven't done any of the calcs but I think that the expression that 200 gal is 200 gal is misleading. If I have a tank that's 1'x1' Square and 8 feet tall it's going to have more pressure then a 1'x8' tank 1' tall.
Also comparing pounds to gal isn't a very good comparison as one is a unit of mass and the other volume.
Just wanted to point that out.
Just the same I would error on the side of safety and go with the thicker glass, especially if you're to lazy to run the numbers like I am

 

[johnny1]

The tank is 1/2in.glass!!! I did not build it. It's a perfecto brand tank remember the thicker you go the greener the glass gets and i dont think i would want it any greener.I dont know anything about building one your self <img src="graemlins//urrr.gif" border="0" alt="[urrr]" />

 

[raysher]

Originally posted by give me fish:
<strong>If I was to build a tank of that size I would go with 3/4" or 1" thick glass. $400 is not much when you concider what it would cost if you went and bought a manufactured glass aquarium. Better to be same then sorry.</strong><hr></blockquote>

 

[diatom]

Sammy~
Thanks for restating that...I like the way that you worded it. It's much more clear the way you put it.

 

[drkegel]

OK, to clarify, 200 gallons will result in the same amount of force (weight) regardless of what shape you put it in. If you mae it a foot wide and a foot deep, the pounds per square inch would be much higher than if you put it in a 4' by 4' square, but the total force is still the same.
I would NEVER use 1/16" glass, way too brittle and not very forgiving in the corners!
As stated earlier, the MOST IMPORTANT part of any aquarium is the quality of the corners!

 

[jedimaster]

I built my own tank(nearly), then I bought one because I got a great deal on a 90 gallon hagen.I did lots of research on the glass thickness issue. Everyone here has parts of everything right.
The preasure exerted sideway(against the front pane of glass) is determined by the height of the water column as well as the depth(front to back). The height plays a much larger roll than the depth but the depth still makes a difference.
The lenght (left to right) also plays a roll but not due to the water, due to the glass itself.
Here are three analogies to help explain why.
1) Water column height
(already explained well above by another poster)
2) Water depth(front to back and side to side)gravity pushes down on the water and then the water pushes out on the tank. The more depth(fron the back you have the more the potential is for the outwards preasure) This is not very significant when comparing an 18" front to back tank to a 3' square tank, so many people just discount this extra preasure
3) Lenght of a pane of glass.
Think back as a kid when you friend would hold up a branch and you would whack it to break it. tehn he holds up the broken piece and you whack it again and break your hand.
You got weaker? the branch got stronger? Nope, ,neither are true. The branch was still the smae strength but the strength(tensil strength I beleive) was spread out over a longer area.
So if you have a 2' by 2' 1/2" piece of glass you could probably stand on it without breaking it. But if you have a 6' by 2' 1/2" piece of glass and try and stand on it, look out below.
Get the idea.
Your weight hasn't changed, the amount of presure you are exerting on the glass hasn't changed but, the glass isn't stronger or weaker... you get the idea.
The last thing to keep in mind is the process of making glass, a longer sheet of glass will have more imperfections than a smaller sheet, even if they are made to the same standard. So the longer the sheet you will have to make allowances for the glass itself.
Having said all that,
for you dimmesions a 1/2" should be fine. in fact if you make it 18" tall and have a full frame around it. 1/4 plate will be more then sufficient. Having said that. My new hagen 90 gallon 4 foot long by 24" tall by 18" deep tank is 3/5" thick.

 

[drkegel]

Thanks for putting into words what I could not. That's why I'm not going into teaching
I think you meant 3/8", not 3/5" BTW. 3/5" is thicker than 1/2". (PGO = Profound Grasp of the Obvious, one of my favorite sayings.)
I'd still go with 5/8" on a 210 gal., but that's just cuz I like a little extra safety factor in my calcs, and because I don't like broken glass and flooded rooms because some rambuncious rug rat got carried away.

 

[drkegel]

Funny engineering story in regard to buiding tanks that this series of posts reminds me of:
They built a 14 story hotel in Columbia in the 1980's. On top of the roof, they wanted to put a pool. So they did, only when they went to fill the pool, the building collapsed because some engineer forgot to add in the weight of the water that was going into the pool!
Including that weight (one would think/hope) would be intuitively obvious to even the most casual of observer!
Bad things happen when you don't take your time and pay attention to detail!