Selecting an Aquarium

Last update: October 17, 1998

Here I am, ready to party! This was our 
original 85 gallon setup with a cinder 
block stand and DIY hood. The clutter 
in the "stand" convinced us to have some 
nice oak cabinets custom made. 

Note the Magnum canister filter, Dupla 
CO2 Starter Set and Tetra test kits. Yes, 
folks, we were once humble ... in 1986!

What is "Best"?

People often wonder what is the "best" tank for a planted aquarium.  "Best" has different meanings to different folks, so most answers are simply opinions, as is ours. We will try to define our criteria for "best" as we go along. One thing we don't consider as part of the criteria is cost even though this is the primary consideration for many aquarists.  If cost is an issue, you might read our suggestions and then try to find a used tank that fits the bill.  Check the newspaper classified ads for used tanks -- there are usually quite a few offered and the prices are usually very flexible.


Generally, bigger is better but there are some practical concerns.  How much space do you have?  How long are your arms? How much weight can your floor hold? How much money do you have? Remember, the bigger the tank, the more expensive all the other required items will be.


If space is not a concern, try to find a tank that is at least 48" (120 cm) long. The main reason is lighting -- the best and cheapest fluorescent bulbs come in 48" lengths. Shorter bulbs are available but there is a more limited selection of types and spectrums.  Also, shorter bulbs tend not to be "instant start" and may cause problems with some ballasts. Lastly, shorter bulbs tend to be more expensive. If you can find a tank a bit longer than 48", so much the better. A 48" bulb and a pair of end caps or bulb holders may be a little longer than 48" and will not fit in a hood whose outside dimension is 48". Most tank manufacturers don't seem to realize that planted tanks require quite a few watts to be successful and the typical pair of 18" 20 watt bulbs isn't going to work!

We actually prefer 60" (150 cm) long tanks.  This is a common European size but 60" long acrylic tanks can be found in the U.S. I believe one manufacturer makes a 60" glass tank, but it is probably a special order. The extra length allows fitting 48" fluorescent bulbs in the hood with no problems.  The extra 12" also seems to make quite a big visual appearance also. When we sit near an aquarium to observe it, we seem to pick a distance from the tank that allows us to see the ends of a 48" tank with our peripheral vision but a 60" tank is just long enough so we don't notice the ends. This gives an optical illusion that the tank goes on forever!

This a 48"x24" 90 
gallon tank. 
This is a 60"x18" 85 
gallon tank. 
This is a 60"x20" 100 
gallon tank.


The wider a tank is the better you can aquascape it.  Having more width allows you to layer different height plants from the foreground to the background.  This gives a very nice appearance and actually makes the aquarium look wider than it really is.

The minimum width we would recommend is 18" (45 cm).  Unfortunately, the most common and least expensive 48" long tank in the U.S. is the standard "55" gallon tank. The "55" is only 13" wide and is very limiting in what you can do with aquascaping. You should consider a "55" only if cost is a big factor in your decision. A 75 gallon tank is the size we would recommend as the smallest "best" tank size.

A 24" wide tank is very appealing and is our next recommendation. The extra 6" seems like a lot more than it really is when you start to arrange plants, rocks and driftwood.  When you initially bring home plants from the store, they seem very small and it is difficult to buy enough to fill the space.  But after a few months of great growth, you will realize how much space some of the larger plants take up when they are mature!  A 24" wide tank will be a great space for those "show" plants you've always wanted.

Wider tanks are available but should be considered carefully. Plants require a lot of maintenance, especially pruning and replanting.  You may find it very difficult to reach the lower rear of a 30" (75 cm) wide tank, especially if it is taller than 18". A few people we know have such wide tanks and they report having to shower before working in the tank for fear of poisoning the fish with underarm deodorant! If you're thinking of a larger tank, try it out in the store first. Make sure it is set up at the height you will have it at home and pretend you're working in the tank.  Lean over it for 30 minutes to see how your back feels.


The taller a tank is the better plants can grow to their full height (or rather, can grow higher than they would otherwise). We have found that all stem plants will grow at least 18" tall, even the ones that aren't supposed to according to plant books. Having a taller tank means more time between trimming  and overall better proportions.

We would not recommend going less than 18" (too limiting) or more than 24" (difficult access).  Also, if the tank is deeper than 24", you will have more trouble lighting it properly and may have to resort to expensive metal halide systems.  Our favorite depth is 22".


There are two types of aquariums available: glass and acrylic.


Glass is generally cheaper up to 120 gallons or so but will be much heavier than acrylic if the glass is more than 1/8" thick (as is typical in standard "55"). Most larger 48" tanks, like a 75 or 90, use 1/2" glass.  A 120g tank (48x24x24) weights 250 pounds empty and can be very awkward to transport and move around. Be sure you have some big, brawny friends if you go with something like this.

Glass is more scratch resistant than acrylic but it still can be scratched if you are not careful. A little rust on your razor blade can leave scratches as can certain "pot scrubber" type materials.  Unlike acrylic, scratches in glass can not be polished out. Worse yet, scratches on the inside will be very visible.  Scratches on the inside of an acrylic tank are mostly invisible.

If you are planning on drilling holes in the tank for filter plumbing, make sure the glass pane you will attempt to drill is not tempered. It is very difficult to successfully drill tempered glass!


Acrylic has some advantages over glass.  The first thing you will notice is a larger acrylic tank is very much lighter than a similar sized glass tank. Acrylic also is clearer than glass -- you won't notice as much of a green tint (unless you fork out a huge amount of money for a custom optical glass tank!).  In lengths of 60" or less, acrylic tanks have the front and sides formed from one piece of material - there are round corners instead of a glued butt joint.  That's usually the first thing people remark on when they see an acrylic tank for the first time.

There are some drawbacks.  Acrylic will scratch much more easily than glass, so if you have kids or pets with claws you might want to shy away. Shallow scratches can be polished out with a fine polishing compound and patience.  Scratches inside the tank are usually not a problem since the index of refraction of acrylic is very close to that of water -- scratches "disappear" when they are under water!  After a few years, you may notice that the inside of the tank is hazy when it is dry (during water changes, for example).  This is due to the very slight abrasive action of the special cleaning pad that is used to remove algae from the insides.  But this haze also disappears when wet.

When we bought our first acrylic tank in 1972, we were concerned about getting algae off the front -- obviously, the usual razor blade was not recommended.  We were assured that algae would not grow on acrylic. Well, let me assure you that algae most certainly does grow on acrylic! But, fortunately enough, it doesn't stick as well as it does on glass.  The toughest algae is the small green spots that grow on the aquarium sides. This wipes right off acrylic with one of those white buffing pads but requires a razor blade to remove from glass.

Drilling holes for filters in an acrylic tank is not a problem.  A hole saw can be used as long as the drill speed is kept fairly slow and the saw teeth are lubricated and cooled with water.  As long as the acrylic is not melting as you drill, there is no problem.

The biggest drawback with an acrylic tank is the top plate that is used for strength.  Unlike a glass tank which is completely open on top or has a small center brace, an acrylic tank has a solid acrylic piece on top with cutouts for various purposes. This limits access to the tank to some degree.  Make sure the tank you buy has enough openings for filters, heater cords and whatever else you use.  Also make sure the main access holes are large enough for you to easily work in the tank. If you buy a large rock or piece of driftwood, make sure it will fit through the access hole! We bought a huge hunk of driftwood once that would not fit in the access hole. Before I started cutting it, I made a cardboard mockup of the tank and access hole so I could remove just enough material from the driftwood but not too much!

An open top is cool!