Originally Posted by ahill3780

Glass aquariums tend to offer slightly clearer viewing of the ecosystem within, but they have plenty of cons. For one, glass contains silica which can over time be released into the water column feeding the growth of nuisance algae such as diatoms. Not a huge problem at all as the rate of release is extremely slow and it is more likely the algae will form on the glass itself where it can be easily wiped away rather than settle in other areas of the aquarium yet it should be listed as one of the arguable cons. Another is the cost of replacing a cracked or broken pane since glass is more expensive than acrylic, both in material cost as well as cutting and shaping the material. However, glass aquariums can offer superior strength over acrylic when it has been tempered. Another con is that glass can offer sharp edges to cut the unwary aquarist - a feature that is mostly lost on acrylic tanks, and good riddance!

Acrylic is truely a wonder for the aquarium hobby! It is light, durable, strong, plentiful, and cheap by comparison! It's cons are far outweighed by its pros. I think the biggest con for acrylic is that it is not easily cleaned since it scratches so easily - you should not use an abrasive material when cleaning an acrylic tank as the resulting scuffs and scratches can be a real boon. Other than that there are many good things that can be said of acrylic. For one, acrylic holds in heat much better than glass does causing your system to maintain a constant steady temperature and not overworking your heating equipment. Another is that acrylic can be easily drilled for when you want to install plumbing or bulkheads for increasing your filtration system, whereas if you were to try drilling a similar hole into a piece of tempered aquarium glass (which is extremely hard, and almost impossible to tell from normal glass) the glass would simply shatter giving you an costly problem to deal with.

Most of the time acrylic wins out over glass as the material of choice for aquariums, but that does not mean that glass is going to be phased out anytime soon - quite the contrary actually.

It is my personal opinion that acrylic should be the material of choice for small to medium sized tanks (5-120 gallon) due to the advantage of being so light. I say this since it is more likely someone will decide to move a smaller tank than a larger one, and the weight difference will be well worth it then! However, if you plan to keep a larger system (150+ gallons) then I would stick with the stronger and more maintenance friendly Glass aquariums.