Marine Topic Of The Week, 10/27-11/3

[steelhealr]

Ok....a very simple topic and frequently the first decision a new marine tank owner needs to decide on startup.

Glass Pro's

1. Difficult to scratch
2. Glass can support considerably more than its own weight over distances. Because of this, glass aquariums can be kept on stands with an open or incomplete top with little or no risk. Glass tanks require less structural support at the top to keep the tank from flexing or splitting its seams under the weight of the water.
3. Glass maintains its clarity over time.
4. Glass is easier to ship and requires fewer specialized tools to work with, so glass tanks tend to be less expensive than acrylic tanks.
5. If a glass pane breaks, it can be repaired with little difference in the clarity/color of the overall tank

Glass Con's

1. Glass is heavy
2. Sharp impacts can crack the glass
3. Glass is brittle and rigid; shapes are usually rectangular
4. Glass must be tempered to increase it's strength, increasing it's thickness and weight. Tempered glass cannot be drilled safely
5. Glass has a different index of refraction than water. Colors are not quite true, position is not quite accurate, size can be distorted slightly. The thicker the glass is, the more pronounced these errors become.

Acrylic Pro's

1. Acrylic tanks are lighter than glass tanks. This means that if you have to move an acrylic tank for some reason, it will be much easier . However, remember that the majority of the weight of a complete tank is the water and live rock and sand, not the tank itself, so you will not save a lot of weight by using an acrylic tank rather than a glass one.
2. 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.
3. Acrylic is easily molded and formed into almost any shape that can be described.
4. Acrylic does not need to be as thick to support the same water volume as glass does.
5. Any acrylic tank can be drilled to accommodate an overflow system.
6. Acrylic has nearly the same index of refraction as water. The only distortion you are likely to see is that the fish is slightly misplaced, but the size and color are true.

Acrylic Con's

1. Acrylic is highly scratchable. Acrylic polishing kits are available in many places, and these can be used to remove scratches on the outside of the tank. These polishes should not be used on the inside of the aquarium.
2. Many types of acrylic will yellow with age, particularly if they are kept under a full spectrum light or are exposed to direct sunlight.
3. Acrylic tanks tend to be more expensive than glass tanks. This is not necessarily because the acrylic is better than the glass, but more often is due to the shipping costs.
4. Acrylic tanks require a stand that will support the entire bottom of the tank, or else the bottom of the tank may pul away from the seams under the weight of the water. Also, acrylic tanks require much more support across the top of the tank to keep the acrylic from bowing apart and either splitting seams or spilling water.

SH

 

[Mr Miagi]

Well it might just be me, but the curved acrilic tanks get on my nerves something shocking. I hate the destorted vision you get from the corners and bow front. I love looking throgh my glass window to my mini reef's.

 

[Eelzor]

I personally find glass better for just a few reasons already stated.

Cheapness

I see these runout sales and glass tanks all ready to go for really cheap prices and several aquariums/petstores quite often. When it comes to acrylic they are with the hood and all and are usually much more expensive. I prefer the box look to a glass aquarium too - more traditional. I agree with miagi about the curved corners, seems not quite right to me.

Scratch Factor

The fact that acrylic is more easily scratched is also a factor. You can only polish scratches when they are on the outside but half the time there on the inside.

I'd say if your a real D.I.Y. kinda guy, then maybe acrylic can be more resourceful for someone looking to customise their tank in some way. The only true drawback I find with glass was in someones post recently when grains got between the algae magnet and the tank glass permanently scratching the tank quite badly. That'd certainly be quite a nuisance.

However one style of acrylic tank appeals to me, the cylindrical tanks. Unfortunatly cost rears is ugly head once again here with a 120G cyclindrical tank (hood+stand) costing $2000AU. I could get a 180G glass (with stand and hood too) for $700AU!

I am interested to hear what other have to say about their preferences too, but I'll leave it there for now.

Cheers

 

[callum_parsons]

i have had both a glass and acrylic tank. and i think that glass in much better my acrylic tank had annoying little scratchs caused by then sand and the algae was impossiable to remove

 

[Siamese Fighter05]

Great thread, thanks for posting SH

 

[andywg]

There is always the economy of size.

Very large tanks jut can't be mae in glass as they become far too heavy and bulky. Almost anything past 250-300 gallons really has to be acrylic. I have moved a 200 gallon glass tank and it is not fun, neither was my double bottomed 6x2x2 tank. Had these two tanks been acrylic then it would have been extremely easy to move either.

Also, glass ends up needing to be a lot thicker than acrylic at higher sizes and so costs begins to swing the other way.

The way I see it, for most tanks glass is best, but once you are into the large tanks acrylic becomes better.

 

[Gankutsuou]

I think either extreem has to be acrylic.

Anything under 3 or 5 should probably be acrylic, and anything 200 +, as Andy said, should be.

Glass could work for anything inbetween.

Also, tanks stuck in a wall and so on should probably be glass, as they aren't going anywhere.

 

[steelhealr]

Unpinned and released. SH