I often get the question of which is better, glass or acrylic, for my
saltwater fish tank? And my answer is, it depends. It really does. So
here I am going to lay out the different pros and cons of glass and
acrylic for your aquarium.
1. Clarity And Aesthetics
Acrylic
is roughly 20% better clarity than typical glass aquariums, which are
made with plate glass. The only exception is for lead-free glass, also
known by the brand name Starfire glass, which has the same clarity as
acrylic. And of course this special lead-free glass is significantly
more expensive than the normal plate glass. 20% Sounds like a big
difference, and the truth is you can really only tell the difference if
you had a normal glass tank sitting right next to an acrylic tank. So,
it is really only makes sense to pay the extra cost for the lead-free
glass (same clarity as acrylic) if optimal clarity is a high priority
for you. Otherwise most people would not notice the difference.
One other benefit of acrylic tanks over glass, is that acrylic tanks
have nearly invisible or see-through seams, while glass tanks use
unsightly silicone seams.
2. Resistance To Scratching
While glass is
more resistant to scratching than acrylic is, there is a trade off to
consider. Glass is less likely to scratch, but any scratches that occur
in a glass tank are permanent. And while acrylic scratches quite easily,
it can be polished out. Although, if you've never polished an acrylic
tank before, even just a small scratch, it's a lot of work (not fun).
One caveat is that glass tanks have become preferred for reef tanks.
Because of all the algae the grows on the glass in a reef tank
(especially coraline algae), reef tanks need their glass to be cleaned
more often and so you are better off with glass which is more resistant
to scratching. One way I know this is that for many years in my aquarium
installation company, we used acrylic for most of our custom reef tank
installations. And after several years, most of them needed to be
polished to remove scratches caused by cleaning glass. No matter how
careful you are when cleaning glass, if you have an acrylic reef tank or
even a fish only saltwater tank, you will eventually have scratches
with acrylic.
3. Weight
Acrylic is
significantly lighter than glass. This is an important consideration for
shipping costs (freight) and load bearing ability of your home or
office to support the weight. And, of course, when it comes time to lift
the tank into position, the lighter the better. And the thicker the
panels, the heavier the tank.
4. Durability
Glass is more brittle than
acrylic. Acrylic flexes when under stress. This flexibility allows an
acrylic tank to handle temporary stresses well. However, acrylic tanks
are only as durable as the quality of their seams and the thickness of
the panels. Over time, acrylic seams tend to weaken. So while glass may
be more brittle than acrylic, glass tanks are actually more durable than
acrylic over the long term
