The Differences Between and the Debate About Glass and Acrylic Tanks

[juggler]

I just tap the different tanks at home with a pen and the vibrations sounded different. The glass sounded distinctly glass. The "acrylic" sounded different -- dull and a bit plasticky.

So I did some arm-chair research. Sieved through several sites and they give the difference between glass and acrylic tanks. Here's something interesting I found, hopefully true.

Glass vs. Acrylic: The Differences Between and the Debate About Glass Aquariums and Acrylic Aquariums

I quote one of the properties of acrylic on that page:

Though a VERY sharp impact will crack or shatter a piece of acrylic, the amount of force needed for this damage is far greater than it is with a glass tank. On the other hand, almost any impact to an acrylic tank will leave a scratch or mark, even those that would not have marked a glass tank.

So that's making it harder to determine which one is glass and which one is acrylic since both can crack under a hammer.

[benny]

The five plan type of small glass tanks available in the market are made of glass, not acrylic, despite the misconception.

On the Japanese label (the removable one) it clearly states グラス製, which means made of glass. The thinness and the clarity sometimes mislead hobbyist to think that it's plastic/acrylic instead.

Cheers,

[leeruisheng]

But it doesnt look glass to me cause it sratches easily. maybe its a composite of glass and plastics. There are lots of grades of acrylic in the market.

[Shadow]

is it possible to mixed glass and plastics to become composite?

5 plan tank sound different probably because of the plastic around the tank on top and bottom, kind of damp the sound

[StanChung]

Acrylic is not as strong as glass. Bends easier. Made a few large arcylic tanks before for shoots. Not very good result as it needs a lot of support at the joints. One actually blew at the corner as we were filling it up. It was a 4x6htx2ft not even 1/2 up. It was distorting so badly that eventually it just popped, filling up the 40X60ft studio with 4" of water and making everybody running helter skelter to turn off the power cables. zzzt!

For acrylic, look it from the edge. Glass is typically green, acrylic is not. [unless it's one of those blue or non-iron glass that cost a bomb]

[ranmasatome]

if you are talking about 5-plan tanks.. its glass.. i've broken one of those too.. and when it breaks and is separate from the tank.. you can definately tell it is glass. The sound you hear when it is on the tank is because of the black plastics that surround it.

[benny]

If you notice, filled champagne glass give a plastic sound when you tap on it. When empty, it should just like glass again.

Cheers,

[valice]

What Shadow mentioned is true as even when empty, the tank doesn't sound like glass and that's due to the black rim, which incidentally allowed 5-plan tanks or Nisso or GeX tanks to have thin glass. But the thin glass is quite scary when there are small nephews or nieces who start "tapping" the glass in excitement of seeing moving fishes in the tank.

ruisheng, strange that your glass scratched easily. It shouldn't be the case, I used those dish-water scrub to clean my GSA and no scratches leh. What did you use to scrub them? Steel wool ar?

But acrylic is cheaper when used to make big tanks right?

And I like the sound of this:

Acrylic has nearly the same index of refraction as water. This means that when you see a fish in an acrylic tank, the light has only be bent once or twice. Because of this, the only distortion you are likely to see is that the fish is slightly misplaced, but the size and color are true.

[leeruisheng]

ruisheng, strange that your glass scratched easily. It shouldn't be the case, I used those dish-water scrub to clean my GSA and no scratches leh. What did you use to scrub them? Steel wool ar?

But acrylic is cheaper when used to make big tanks right? And possibly lighter too right?

I tried sratching with penknife. maybe too sharp and forceful? mmm..so it seems it's glass. I've read from net and it says acrylic is more expensive than glass tank. not sure relation with size. But which is more expensive? A 2ft acrylic tank or a 2ft glass tank sold in lfs?

[valice]

Most likely so. It should be able to make some indentation on the glass. It could be the angle you put the knife to the glass. The tip will make the scratch, but if the blade is parallel to the glass, the pressure should not be able to scratch the glass.

Why don't you use something else?

[leeruisheng]

no la enough testing already. cause every cut made will affect the withstanding pressure strength of the tank. one day my tank will leak. haha. Which is more expensive, a five plan 2ft or a rimless 2ft glass tank?

[Shadow]

I think any tank with silicon glue is glass tank because I tried to glue acrylic pipe using aquarium graded silicon glue without success. It won't stick, gues silicon and plastic can't mix.

[leeruisheng]

I think any tank with silicon glue is glass tank because I tried to glue acrylic pipe using aquarium graded silicon glue without success. It won't stick, gues silicon and plastic can't mix.

It's possible. I did it for my acrylic partition. And holding strong. Silicon does not adhere permanently to glass also. So it could be easily be remove by peeling action.

[|squee|]

Interesting!

http://www.iaquatic.com/

Under their "Why Acrylic?" section...

::Lighter
Acrylic is about 48% the weight of glass. Two people can carry an eight feet (300 Gallon) aquarium, while it would take 4-6 people to carry the same aquarium made of glass.

::Stronger
Acrylic aquariums are up to 17 times stronger than glass aquariums. This gives acrylic aquariums, especially larger ones, a wider safety margin when it comes to the possibility of a tank breaking.

::Flexible
Acrylic is not rigid, it has give. If accidentally bumped into the chance of an acrylic aquarium breaking is much less than its glass counterpart. If an acrylic aquarium is damaged it would crack slightly as opposed to exploding.

::Clarity
Acrylic allows 92% of light to pass while glass only allows 70%. This means that you see more of the true colors of the fish. With good filtration, the fish seem to be in the air, as if the wall wasn't there.

::Isolative
Acrylic is a thermoplastic. It holds heat/cold much better than glass. If you have a power failure, your acrylic aquarium will take much longer to cool down/heat up than a glass aquarium.

::Machine able
Acrylic can be cut, drilled and machined easily with minimal loss of strength. Glass loses much strength when drilled.

::Seamless
Acrylic can be molecularly bonded; melted together. The aquarium becomes a one-piece unit. You will not have the problem of leaks or seams splitting which is an inherent problem with glass tanks over a period of time.

Just some reasons....

[Shadow]

the website "water" applet is nice

wonder, is there any reinforce scratch resistance acrylic?

[StanChung]

acrylic

Yes, it seems to have a lot going for it compared to glass.

[juggler]

Interesting discussion...

Anyone seen any acrylic tanks for sale in LFS? Or any item made of acrylic that we can compare?

[grey_fox]

My 5 footer is made of acrylic. Apparently it gets scratches every now and them when cleaning with dish washer sort of sponge. Kind of irks me when I see those scratches actually.

[valice]

Wow. Even dish washer sponge scratches it? Then it is really very easily scratched.

How thick is your acrylic?

[grey_fox]

If I recall clearly its either 12 or 14mm, however on closer inspection, it looks like 2 x 6mm pieces of acrylic pieces, one acting as an outer wall and one as the inner wall, don't really know how to put it to words.

Or then again, it might be my eyes playing tricks on me.