One of the most common questions we get from clients and people in the aquarium hobby is “What aquarium is better? Glass or Acrylic? What’s the difference?” Being around glass and acrylic aquariums for so many years, my recommendation is to change this question a tad and ask yourself: “Which aquarium is going to work better for ME?” In the article, we will cover some of the pros and cons of each so you can make a decision on what will be the best aquarium for YOU.
Let’s start with the basics…a glass aquarium is simply glass panels joined together with silicone. As far as I am aware, this is the sole method for building a glass aquarium. In most cases, the silicone is either clear or black and there is no quality or structural considerations here – just visual. Most aquariums are built with a tempered glass bottom for strength and the rest of the panels with plate glass. You will also encounter two types of glass…regular and low-iron glass. Again here the consideration is purely visual as they are both equally strong…low iron glass is made from a different sand type which contains less iron which makes the panel much clearer and without the green\blue tint regular glass has. Glass has less insulation capability and that can be a pro or a con depending on the room temperature and the aquarium temperature you are trying to achieve.
The Good News:
(1) Glass is going to be less expensive than acrylic in almost all cases. Very large tanks made of glass can be as expensive as acrylic pricing, but at these extra large sizes glass is typically not a good option and we will cover that in the paragraph to follow.
(2) Glass is less resistant to scratches and this is a fair consideration when choosing a fish tank. Having owned several before and working with them now I can say with certainty that they can take a lot of friction without scratching but can still scratch if mistreated with a sharp object and enough pressure.
The Bad News:
(1) Glass is heavier than acrylic – as much as 10 times heavier! Most times this is a non-issue especially when dealing with smaller sizes – the aquarium is not too heavy to transport and the floor it’s on can hold the weight safely. When dealing with large tanks weight can become a consideration especially with raised foundations where the weight may cause a dip in the floor or worse – this too can be overcome by reinforcing the floor. Transport and placement can be more challenging with large glass tanks but could be overcome with the proper equipment and/or number of persons carrying the load.
(2) Glass can break – to be completely fair this is very unlikely but has to be mentioned. If you accidentally slam a rock onto the glass panel or something heavy that is moved around the aquarium hits it, the aquarium can break – but again this is very unlikely to happen but is important to note and remember.
(3) Seams are not as strong – as we mentioned in the beginning, the aquarium is held together with silicone seams. Again, to be fair, if you purchased an aquarium from a reputable company, chances are your aquarium will be just fine for many years. However, we receive a few calls per year asking us to repair leaking seams – this is especially troublesome if the aquarium is built into a wall or custom cabinetry. Last year we received a call about a 250g leaking glass aquarium that was custom installed into a wall with custom cabinets. A pinhole size leak developed over time and the aquarium had to be drained, animals transported into holding bins, sand removed, dismantle cabinets and break the wall, and remove the aquarium to be delivered to the manufacturer for repair – a nightmare for sure. Another consideration for us here in Southern California is the possibility of an earthquake. Even a small tremor can break a seam or cause a crack from a bulkhead hole
The basics….acrylic aquariums are made from a transparent thermoplastic (aka acrylic or plexiglass sheets). The important thing to understand is that acrylic panels in a fish tank are not glued – they are bonded. The water-thin acrylic cement softens the plastic surfaces and allows them to merge. The materials intertwine and literally become ONE piece. The thickness of the aquarium panel will vary depending on size and height but the view of the aquarium display remains as clear and undistorted no matter the material thickness. Acrylic is easily drilled and cut and can make many different shapes that are more challenging with glass. Acrylic has more insulation capability and that can be a pro or a con depending on the room temperature and the aquarium temperature you are trying to achieve.
The Good News:
(1) Better clarity – acrylic allows more light through it as much as 93% where glass can be more in the 82% range. This advantage in acrylic clarity allows for a more natural display and an overall better viewing experience. I recall looking into my own acrylic aquarium after the panel was cleaned from algae and forgetting there was something between me and the fish.
(2) More durable – acrylic aquariums are far more durable than glass. The material is shatter resistant and unlike glass the acrylic sheets are welded into a single piece. This is a huge advantage in my mind, especially when creating aquariums for other people where we are liable for any potential problems. As mentioned in the glass section above, earthquakes are an important consideration for many folks and having an acrylic aquarium helps most people sleep better at night.
(3) Easy to modify – acrylic could be easily drilled and cut to make not just aquariums but sumps and overflows. It is great for DIY projects and simple tools can be used. I recall having to seal an extra hole in a bottom panel which was super easy by just welding a 1/2″ sheet of acrylic over the hole to create a patch fix.
(4) Lightweight – acrylic aquariums are much lighter than glass making them much easier and cheaper to transport and place in a home or business. The lighter weight of acrylic can also help you avoid any floor reinforcements needed at times for big glass fish tanks.
The Bad News:
(1) Scratches easily – the main disadvantage of acrylic aquariums is the likelihood of scratches. Any abrasive material inside the aquarium like a rock or gravel/sand can scratch the inside of the panel and something as simple as a belt buckle or wrist watch can scratch the outside panel. I recall reading threads on forums to determine what aquarium type I wanted for my aquarium and often found myself horrified by some stories told about acrylic scratches. After owning one and servicing hundreds of them I can say with confidence that if you are careful and use the right tools you will not scratch your fish tank. So it comes down to one thing – be careful and cautious. The good news is that most scratches could be buffed out inside or outside the aquarium with inexpensive scratch-fix tools or by paying a professional company to fix it such as www.seaclear.co
(2) Expensive – acrylic is more expensive than glass – that is the price you will pay for the several advantages mentioned above. This could be a non-issue with someone with the funds to pay for acrylic but for most people cost is an important factor and it is a serious consideration. Decide for yourself what makes sense for you and how much you can allow to invest in your aquarium.
As we have covered above, there are many considerations when choosing a glass or an acrylic aquarium. If I had to sum up the above with a practical example I would say this: If was setting up an aquarium for me that is under 200 gallons and free-standing (not built into a wall \ cabinets) I would probably do glass to save me some money and have the ability to deal with any issues by easily removing it from the stand. Now, if I had to set up the same size aquarium for a client I might suggest acrylic simply for liability reasons – after all we have a business to run :) If I were to set up anything bigger for me or for a client whether free-standing or built-in I would choose acrylic because at larger sizes glass and acrylic prices come closer and the safety factor becomes more relevant with more water volume which can cause a bigger problem should it occur. My hope is that I did not scare anyone here by talking about worse case scenarios and problems. To put things into perspective I have lived in Southern California as an aquarium hobbyist and business owner for over 20 years and have only experienced one failed glass aquarium seam that caused a leak and one used acrylic aquarium brace that came apart. I hope that I was able to give you the proper information to make a decision on what aquarium type you will choose.