Published November 13, 2012
If you're going to keep fish in your house, you're going to need to put them someplace! Historically, glass has been used but for the last 50 years, acrylic has become a very popular material for fish tank. This article covers the History of aquariums, common sizes, pro arguments for using glass tanks, con arguments for using glass acrylic tanks, and online sources for you.
History of Fish Tank Materials
People have kept fish for food or fun for at least the last 4,000 years. Keeping fish in aquariums is a much more recent development. Keeping fish in glass bowls developed in the mid 1700s. In 1805, Robert Warrington developed the first sustainable glass aquarium. He did this by understanding the need to cycle the nutrients in the water for the fish.
Aquariums during the Victorian age were slate or steel bottomed tanks which were heated underneath with open flames! Their tanks were glass panels attached with metal frames. It wasn't an innovation in actual aquariums but innovations in filtering systems that really moved the home fish keeping hobby into the forefront in the mid 1950s. Aquariums had their own moment of innovation in the mid 1960s where glass sealed tanks replaced glass framed tanks. Silicone based adhesive was used to cement glass panels together. Acrylic tanks were offered to the public in the early 1970s.
Common Glass Tank Sizes
Glass tanks come in all different sizes. Small tanks usually start at 10-gallon. Experts recommend that you go no smaller than 20 gallons for a freshwater tank and 30-40 gallons for a marine tank. Usually, you'll find glass tanks in the following sizes: 10, 20, 25, 29, 55, 75, and 90 gallons. When you pick tanks, consider that wider and longer are usually better than taller given the same volume. That's because a tank that is wider and longer will provide a larger water surface area. A larger water surface area helps promote oxygen exchange which is good for the fish in your tank.
Pros of Glass Tanks
Even with the advent of the acrylic aquarium, there are still many reasons that people stick with a glass tank. Advantages that glass tanks have over acrylic tanks include:
- Glass tanks are cheaper than acrylic tanks
- Glass tanks are more scratch resistant
- Glass tanks won't yellow over time the way acrylic tanks will
- Glass tanks don't need as much brace support the way an acrylic tank needs.
Even though you might be able to buy a smaller loss-leader acrylic aquarium for cheaper than you would spend on a glass aquarium, overall, you'll find that glass aquariums are cheaper than acrylic tanks. For example, a 20-gallon glass tank will set you back roughly $50 whereas an acrylic tank of the same size will cost anywhere from $130 to $140. That's almost three times the cost! When you start getting into really large tanks, the price differential disappears.
While acrylic tanks are stronger over all in terms of resisting breakage, the cold truth is that acrylic tanks can be prone to scratches. Glass tanks are definitely more scratch resistant.
Although this difference may be overcome in the future as more UV-resistant acrylic is being developed, for the time being, fish hobbyists concerned about yellowing over time will always pick a glass tank. Why? Because a glass tank won't yellow over time the same way an acrylic tank can. Most glass tanks will give your aquarium a slight green tint and acrylic tanks will give a bluish tint. For a price, you can get a more color-free view via a glass tank. You can purchase color-free glass (it's expensive). Color-free acrylic is not available.
Another concern where glass tanks stand heads and shoulders over acrylic tanks is that larger glass tanks don't bow to the weight and won't need the extra support the way an acrylic tank needs. While smaller acrylic tanks may only need support on the bottom, you'll find that larger acrylic tanks need brace support, a frame really, to keep the sides from sagging out. You won't have this problem with glass tanks, at least not with smaller or mid-size ones. Larger glass tanks will usually have one central frame to combat bowing.
With all the advantages of glass tanks that we outlined above, you might think that it's a no-brainer to go with a glass tank. If that were true, then pet stores wouldn't be selling as many acrylic tanks as they do! Read on to find out the limitations of glass tanks. Problems with glass tanks include:
- Glass tanks are almost two times as heavy as acrylic tanks
- Glass tanks are not as crack resistant as acrylic
- Glass tanks provide less insulation than acrylic
- Glass tanks don't come in as many interesting shapes as acrylic does
- Glass tanks hard to find online since many shops won't ship them (due to weight considerations and potential for cracking)
Even after manufacturers perfected the waterproof glass tank by applying silicone cement to the seams, there were still a few main problems where acrylic tanks have an advantage over glass tanks.
The main problem with glass tanks is that they are heavy! A glass tank weighs over twice the weight of an acrylic tank of the same size. For example, a 20-gallon acrylic tank weighs 17 pounds. A 20-gallon glass tank weighs over twice that - about 35 pounds.
Glass tanks are also not as crack resistant as acrylic tanks. Glass is just more fragile of a substance than acrylic. This makes it harder to cut glass tanks when you need to customize them to accommodate your plumbing. It's not impossible to cut glass, but you just need to have special tools and know what you're doing. Some of the larger glass tanks are made out of tempered glass. This glass cannot be cut outside of a factory. You can get custom made glass tanks that are built to your specifications, including predrilled holes for plumbing.
Glass tanks provide less insulation than acrylic tanks (and hence aren't as good at retaining heat and keeping tanks warm). Generally speaking, acrylic tanks provide about 20% more insulation than glass counterparts. While this may work against you with a tropical aquarium, it may not be as much a problem with a cold water tank or even preferred with a reef tank (where it can be harder to keep temperatures down due to stronger lighting)..
Glass tanks generally don't come in as many interesting shapes as acrylic does. On the high end, you can get some pretty fancy blown glass spheres and the like but as far as your typical type of tank, you'll find many more interesting shapes in acrylic. Glass tanks usually come in either rectangle or square shapes. You can find some hexagon shapes by the high-end manufacturers. Both All-Glass Aquarium
and Oceanic Systems
make a Bow-Front aquarium which is a glass aquarium with a bowed front. This bow front provides an interesting view with a wider front perspective.
Finally, the toughest thing to deal with when buying glass aquariums is that you'll find them hard to find online. Most shops won't ship them and if they do, the shipping and handling costs can be high. You may need to visit a local dealer to buy one. If you go glass tank shopping, here is a list of reputable glass aquarium manufacturers:
- All-Glass Aquarium has been providing glass aquariums since 1967. Their products are quality made and come in different shapes, styles, and sizes. They make glass aquariums up to a 210 gallon model which measures 72L x 24W x 30H. This tank weighs 2,450 pounds when filled! Make sure your mind is made up before you set it up. You cannot buy their aquariums from them online but they do provide a "local retailer finder" tool on their site.
- Oceanic Systems also has a good reputation for building quality glass aquariums. They also make tanks that go up to 215 gallons. They offer many different shapes, styles, and sizes. They also offer a "local retailer finder" tool on their site.