Going BIG...

I was talking to a customer over the weekend, and he was excitedly relating to me the plans for his newest aquarium, a 300 gallon mega community tank display. He told me all about the cool lighting, the crazy pumps, the fancy gear and water change systems and all kinds of cool technical aspects of his upcoming mega-budget super tank. As I listened, I couldn’t help but reflect that the basis for the phone call was an issue he was having with keeping some very basic fishes and plants alive. In fact, the customer said that almost everything he bought for his 55 gallon tank died within a few weeks after getting the animals in his system. He performed “some” water changes, and tested “some” parameters (most of his water parameters were “perfect”, according to him…oh boy…I knew what I was dealing with now.)

And this guy was about to embark on a five-figure, mutli-hundred gallon mega aquarium system. Does he have a clue at all? I thought. I mean, his assumption was that his troubles with fishes would simply vanish if he built a larger tank. Magically, all of the skills and experience he lacked in 55 gallons would be remedied by increasing his tank by 245 gallons….And this was after I (and a couple of other people) talked him out of going “reef” for this new tank!

I did what any responsible seasoned aquarist would do: After I told him how cool all his gear sounded, I asked him if he was up to the challenge. Well, the retort was a bit angry, actually. I mean, the guy was ready to drop around 25 grand on the tank, so therefore, he felt that this meant he knew what he was doing. “I’ve been researching this reef for MONTHS,” he proudly retorted.

I was like, “Seriously? But you can’t keep a darned fish alive?” 

Somehow, in his head, he felt like he felt like he “paid his dues” with his smaller aquarium,  and that he was ready to go “to the next level” (his exact words) with this sparkling new mega tank. I did my best to gently dissuade him fro making such a huge commitment with his limited experience and skills. I’ve seen this type of looming disaster before- we all have…And the ensuing train wreck that is likely to emerge will not be pretty. It will suck mostly for the animals that will die because of his incompetence and arrogance. It will suck for the people that built the fine quality components that he will no doubt misapply. It will especially suck for him, because he will not get the joy you get from progressing naturally in the hobby and building carefully upon successes. It will suck for the hobby in general, because, although he’ll add to the hobby economy for a short time, his failure will cost it in the long-term. It will NOT suck for the predators on the forums that will snatch up his equipment at volume prices when he calls it quits and sells everything at a huge loss.

I may be a a bit cynical, but I’ve been a round the block a few times, and I can smell a disaster when it is looming.

In the aquarium hobby, much like in life, we're often led to believe that "bigger is better." A large house is better for your growing family! The large bottle of pasta sauce will make 3 nights of lasagna! And of course, the large can of paint is a better buy, right? Well, more often than not, the reality soon sets in'¦The larger house means a larger property tax bill, the large bottle of pasta sauce goes bad after a week or so, and that large can of paint hardens to uselessness before you ever get halfway through it!

Okay, our aquariums are not bottles of pasta sauce or cans of paint, yet there are some useful analogies we can draw from the comparisons. Much has been written abut how larger aquariums are a better way to go for most hobbyists. But are they really the best for everyone?

Let me start of by stating that I have nothing against large aquariums. In fact, until very recently, the smallest aquarium I've kept in the past five years is 150 gallons. Before I blast the whole institution of "Bigger Aquariums Are Better", and anger everyone who owns a deluxe aquarium, let's look at the true advantages of larger aquariums.

Let's define what I call a "large aquarium". As far as this "fish geek" is concerned, a large aquarium is anything over 100 gallons. Or you could look at it from a more practical standpoint: "large" is any size of aquarium that will result in chiropractic bills if less than three people attempt to lift it. "Large" is any aquarium that will result in weather patterns forming in your living room as a result of the moisture. "Large" is'¦well- you get the picture.

Just what are the advantages of keeping larger aquariums? To begin with, larger aquariums aquariums do offer a more stable environment. Larger water volumes retain temperature better (acting as heat sinks), hold more oxygen, maintain chemical balance longer, and dilute metabolic waste easier, by virtue of volume (provided the aquarium is not overcrowded, and that common-sense husbandry techniques are employed).

Within reason, larger volumes of water (especially of greater surface area dimensions) allow you to keep greater numbers of fishes, or larger specimens. Again, common sense must prevail. If your fishy "career" includes a legacy of overcrowded 50 gallon tanks, there's a really good chance that you'll repeat the same thing with your 200 gallon aquarium. It may take a little longer (and cost a lot more), but it happens.

Of course, larger aquariums provide more space to develop dramatic aquascaping schemes. You can utilize those huge pieces of rock and wood that look absurd in smaller aquariums. You could actually build up a 6 inch substrate and still have room for rocks, water, and livestock.

Finally, there is the topic of aesthetics. A large aquarium can become a dramatic focal point in the room in which it is situated. Relaxing on your comfortable couch in front of that enormous tank stocked with colorful fishes and plants is an activity that never gets old.

Yep- big tanks are pretty cool. They're also expensive to purchase. And they're a bit tougher to work with. And they cost more to operate. And they take longer to stock. Wait, where am I going with this? Let's take a look at a few of the "cons" of purchasing and managing a large aquarium.

Wow, the darned things are expensive! It sure takes a lot of glass or acrylic, of proper thickness, to construct a large aquarium. It also takes experience and craftsmanship to construct one safely. That experience and quality comes at price. You don't want to skimp and try to save a few bucks by using thinner materials or lower quality workmanship. Imagine 200 gallons of saltwater spilling onto your new hardwood floor in the middle of the night when your "bargain" tank splits its seams. That's not a fun experience.

If you're purchasing an acrylic aquarium, remember that acrylic is a petroleum-derived product, and as such, is subject to the price fluctuations of the global petroleum market. Thus, acrylic prices tend to soar in "bear" markets.

Glass, too, is subject to price fluctuations and availability. Have you priced a 250 gallon aquarium constructed of "low iron glass" lately? Sit down before you do, because we're talking about some serious money.

Of course, large aquariums require large stands, or more precisely, stronger stands, capable of bearing the tremendous weight. If you want nice, decorative hardwoods or other "designer" materials, the price escalates. Sure, you can save some cash and make one yourself it you've got the DIY gene and a sharp mind for calculating loads. Unfortunately, most of us don't, and our wallets are a bit thinner as a result.

When placing a large aquarium in your home, you want to make darned sure that that your floor can support the immense weight. If your home is built over a crawl space, or if you're locating the aquarium upstairs, you'll definitely want to consult a structural engineer before settling on a resting place for your new aquarium.

Once you have your tank in place, you're probably going to want to fill it with water at some point, huh? I thought so. Wait a second. Did you think about the equipment that you'll need to properly outfit this monster aquarium?

Large aquariums generally require large water pumps to move significant volumes of water. They also need properly-sized sumps and filters to handle the system, not to mention, appropriate protein skimmers, calcium reactors, and lighting systems. You simply can't run a large tank with a small or under-sized filter. Large filters are pricy items, as are large heaters and other gadgets. 

Lighting a large aquarium can be another very expensive proposition (are you sensing a pattern here?). I know marine aquariums hobbyists who run thousands of dollars worth of LED lighting over modest-sized tanks. Have you priced these lighting systems lately? It's a whole new ball game when you require 6 to 8 pendants over your tank. 

Of course, with all of these fancy (yet necessary) gadgets, there's that other ongoing expense- electricity. Running a large system can literally cost hundreds of dollars every month in some areas. I know more than one hobbyist who spends over $1,000 per month on electricity for their large systems, and I'll bet you could find a few without too much effort.

Electrical costs are a very serious consideration when running any tank, but they can be "deal breakers" (and they can trip circuit breakers) with large aquariums. Speaking of circuit breakers- you'll probably have to do some modifications to your home's electrical system, such as adding a new sub panel, to accommodate all of the gadgets in your new tank. Consult an electrician familiar with local codes and safety requirements during your planning phase. Your life- and your family's lives depend on it.


Be sure to purchase the larger sizes of your favorite additives, foods, etc.- you'll need 'em! How much water do you go through in a 200 gallon tank every month? Well, if you change 10% per week, that's 80 gallons. An ongoing expense that adds up. I mean, how many showers is that?

Deep substrates are pretty cool. "Conventional aquatic wisdom" (I love saying that-as if there is such a thing.) suggests a 4" plus sandbed in a 72" X 30" tank would require a minimum of 450 pounds of substrate material. How much that will cost depends upon the material you choose.

Yeah-But What About The Fish?

The best part of a large system is that you can keep more fish in it. Usually, that is. Think about it. If you really like big mean cichlids, you can finally get that large one that can reach 12 inches long. The problem is that, in a large aquarium, this guy will reach this length! And, in the process, he'll give off a lot of metabolic waste. By the way, he's unlikely to be any friendlier at 12" than he was at 3", so think about that when contemplating keeping some of these big guys.


Ah, you like smaller fish, right? You're in a better position. Of course, if you like really small fishes, like I do, you'll spend a whole lot of time just trying to find them in a large aquarium. Trust me- I do. This is actually kind of fun, but to the casual observer, it's kind of weird (Well, so are a lot of the things that we do in this hobby.). So, you'll probably want to put more fishes in the aquarium to help "fill" the space. You'll be surprised how many Cardinal Tetras at $2.00 a pop it takes to accomplish this.

Wood and rock is an integral part of most marine systems. Depending upon your goals, you'll probably need a significant amount of these materials for a large aquarium. In some instances, I know guys who spent so much on these materials that you could purchase a small car for the price of the rock  and wood it would took to fill their mega-sized aquariums.

If you're a plant geek, you'll spend a lot of time and money stocking your new system. Patience can help, because those small cuttings that you get from your friends can and will grow into large, impressive specimens given time and space. Of course, this is true with any sized system, but it is a key to keeping this aspect of large aquarium keeping more affordable.

It's Your Call:

All of this seemingly negative talk about the challenges of setting up a large aquarium is not presented to discourage you from setting one up. However, it is presented to give you a sort of "reality check" as you contemplate a large system. It's easy to fantasize about the huge aquarium that you're going to build when you win the lottery. It's quite another to actually set it up if you're of more modest means. In reality, it's usually necessary to compromise somewhat based on budget, space, time, etc.

Remember, despite what you might see and hear, having a large aquarium does not brand you as a "success" in our hobby, any more than maintaining a smaller system brands you as a novice. It's not like you crossed over some imaginary barrier and arrived as a "serious" hobbyist. Success in the hobby is about creating and maintaining a vibrant, healthy aquarium, regardless of size, for the long term growth and prosperity of its inhabitants.


Yes, large aquariums are impressive. But I've seen plenty of large aquariums that were downright unremarkable (in fact, I've set up a few, myself). Many hobbyists set up huge systems as the "next phase" in their aquarium career, and some end in disappointment- or even disaster. If you're not able to master the art and science of aquarium keeping with a small system, a large tank will likely not be any different for you. Think before you leap.

Large aquariums can be visually arresting, beneficial to their inhabitants, and just generally add a new dimension of fun to your hobby. However, the time, money and commitment to maintain them are a serious consideration. Keeping a large aquarium is not an endeavor that you enter into lightly.

Enough said...for now!

Scott Fellman

Tannin Aquatics

Scott Fellman
Scott Fellman


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