Acrylic vs. Glass

[LBDave]

I think acrylic tanks are great for a lot of reasons (weight, strength). But I had an acrylic tank that developed what looked like fracturing internal to the acrylic. Looked horrible.
I theorized that it was sunlight due to the side of the tank where this occurred.
Acrylic also scratches easier but I never felt that this was a huge deal.

But now on this go around in the hobby I am sticking to glass due to what I mentioned above. I am curious (all the time on a bunch of stuff....) about what MFK members prefer for their tanks.

BTW back in the day I hated glass because meds would color/stain the silicone. Now days that is not so much of a problem due to modern construction techniques and meds.

 

[Lepisosteus]

The crazing you noticed in the glass was likely caused by cleaning the tank with something you shouldn’t have. Did you ever use: windex, ammonia, acetone, an alcohol based cleaner, a solvent based cleaner on the tank? Acrylic will not craze from sunlight. Discolor is not unheard of and can be caused by UV but should not occcur for a tank kept inside. Windows tend to block out most UV as well

 

[Lepisosteus]

I personally love acrylic tanks. far superior to glass in my opinion.

 

[LBDave]

I personally love acrylic tanks. far superior to glass in my opinion.

I don't think it was due to a chemical. It was like "in" the acrylic. The outside surface was smooth. And it started on one side of the tank (a hex) and grew.

 

[LBDave]

I don't think it was due to a chemical. It was like "in" the acrylic. The outside surface was smooth. And it started on one side of the tank (a hex) and grew.

And I sort of agree with you on acrylic. I have had both. Back in the day acrylic was deluxe and glass was poor mans. Maybe it's still this way I don't know. I am getting a tank with bent glass corners which I think will be interesting.

 

[Poseidon2.0]

I have just gotten my first acrylic tank last month. I like it so far and plan to replace my 75 glass with a 120 acrylic this summer for Darth Vader (my oscar). Are there particular brands that one should avoid? I am assuming that, like with glass, custom jobs are typically better quality. I got a "Clear for Life" for my first one since Walmart had them are for about 1/2 the price of other places. So far so good with the new tank, in any case. Really clear.

 

[Lepisosteus]

I don't think it was due to a chemical. It was like "in" the acrylic. The outside surface was smooth. And it started on one side of the tank (a hex) and grew.

Crazing occurs anywhere. The stresses can be visible on the external surface or internally. Crazing is internal stresses within the material. It could have occurred from excessive bowing caused by undersized material

 

[LBDave]

Crazing occurs anywhere. The stresses can be visible on the external surface or internally. Crazing is internal stresses within the material. It could have occurred from excessive bowing caused by undersized material

Interesting. Learn something everyday.

 

[FINWIN]

I agonized over the decision when I ordered my custom tank for quite a while. After weighing the pluses and minuses I went with glass. Plus, the acrylic had huge bracing at the top that would've prevented me from putting pieces in I wanted and limited the type of filtration I wanted to use.

Size, short term and moving big tank = acrylic
Long term durability and clarity = glass

Just couldn't deal with all the special care /tools acrylic would need for cleaning. Even leaning against it for maintenance scratches (zippers, buckles, etc). No one I knew recommended acrylic long term although I still wouldn't mind an acrylic smaller tank (say 100 gallons or less). And even now all the old acrylic tanks I see look like milk or dingy.

Then you have catfish and plecos that can leave sucker scratches, be careful cleaning substrate against the walls, on and on. Not saying it can't be done but I was like, meh.

You're also limited with backgrounds for acrylic unless you velcro fabric on. Acrylic does uv fade over time because of a chemistry change so clarity is lost even if you polish it. The material itself does this and it isn't just reliant on sunlight. You can delay it for awhile but that's it.

 

[Lepisosteus]

Why are you limited with backgrounds? As for clarity, acrylic is far clearer than glass. Acrylic distorts less than that of glass as well. Yes it becomes milky if improper cleaners are used.

Acrylic does scratch relatively easy compared to glass. I say relatively for a reason. Many people believe that acrylic scratches like nothing. It still takes a fair bit of effort or lack of care to scratch acrylic. I say this as I had a 6 year old 500 gallon tank without even a scratch by the time I emptied it. Most believed it was still new. I also make custom acrylic tanks so I won’t knock acrylic Unless you clean the tank with sandpaper there is no reason you should be scratching acrylic as badly as people say. A lot of people complain about scratches caused by substrate getting into magfloats. The same thing happens on glass tanks as well. I made a post on this over 2 years ago. The hardness of glass is 5.5. The hardness of most substrates will be 5,6,7. The hardness of acrylic is roughly 3-4. So, using most freshwater substrates, composed dominantly of quartz with hardness 7 will scratch acrylic easier then glass. As you can see though the same substrate can scratch glass. For freshwater use they are very similar. The difference comes in saltwater. Hardness of coral skeleton or aragonite used for reef tanks is 3.5-4. So, when using reef substrates, acrylic will still scratch while glass will not unless there’s impurities within the mix (not purely aragonite). Why this is relevant: a lot of what’s common knowledge in this hobby is taken from reef sites such as reefcentral, reef2reef. There is always a bias.