water pressure? answer

[daninthesand]

Either tank has the same pressure on the sides.


Doubt that? Think about this then...if you take your hand and place it 10 inches down into a 5 gallon bucket, would it not experience the same pressure as if you stuck your hand 10 inches down into lake Erie?


(We are assuming here of course that the two bodies of water :ie the bucket and the lake, are at the same altitude, and have the same water density, which of course is unlikely with all that sewage, oil and other crap in the lake.)


Whats my point?

Think about this next time you build an aquarium. If you have the room to make it wider and longer, do so. The abiltiy to use thinner glass will make it cheaper. And generally the tank will be safer too

Daniel

Refer to this post to figure what the heck I'm talking about ;D
http://forum.simplydiscus.com//index.php?board=1;action=display;threadid=14732;st art=msg152442#msg152442

[Dave C]

I doubt that. While the water pressure may be the same the strength of the glass is much less because of the length. I doubt that a 1 mile length of glass would stand up unsupported, it would bend and break from the pressure of the water. So I agree that the glass could withstand the pressure but not without some support. So if you're going to make a 6' x 1' x 1' tank out of 1/4" glass make sure you include some top braces to keep the glass from bowing out.

[daninthesand]

Of course a mile was just an exageration. And also of course you need bracing. You had doubts Dave...but of course.

[Dave C]

I understand it was an exaggeration dan. And I wasn't trying to nitpick. But I'd hate to see someone build an 8' long tank 10" deep and think that it would be as strong as a 10" long tank and therefore not put any bracing on it.

btw, when I had my 55g tanks made I needed them to be 24"x30"x18" to fit two on a shelf. I intentionally made them with 3/8" glass so I could get away with no braces. Sometimes thicker is better!

[ronrca]

Both are correct! ;) While the pressure of the sides of the glass remains the same at any given point, you do have to take into consideration the lenght. Unsupported it will crack but that is an easy fix. Put some braces every 2 feet or so and you can have a tank 1 mile long! ;)

I have asked myself that very same question Dan because I need to build some larger tanks. By keeping the tanks shorter but longer, I can accomplish this (using braces of course). The taller the tank, the thicker the glass. The longer the tank, the more braces required.

However, another factor needs to be considered. Increasing the volume will increase the weight on the bottom glass of the tank. Therefore, the bottom will need support also unlike the tanks that you buy in the lfs (raised off the bottom by an inch). ;)