You've seen them at garage sales, those empty fish tanks. Maybe somebody bought it on a lark after seeing those lovely fish in the pet store. They brought it home, put it by the windowsill, filled it with water and gravel and plastic plants, added a few fish, and enjoyed their new pride and joy. At least for a week or two. Then came the algae, and the cleaning, and the sick and dead fish until eventually the tank was drained empty and put out with the old encyclopedia set and last year's snow pants.
Maybe this story sounds a little too familiar. Or maybe you've been afraid of getting a fish tank because you don't want the hassle. If you have always admired aquariums but thought that they were just too much work to keep, then you need to know a few tricks which can make setting up and keeping an aquarium much easier and more relaxing. Aquarium maintenance does not need to be a headache. This article is written for the beginner to intermediate fish keeper, so certain assumptions are made regarding the tank; namely that it will be freshwater, that it will be a community tank with different kinds of fish from around the world, and that it will have plastic plants rather than live plants. First let's examine seven common mistakes and how to avoid them.
The first mistake people often make is thinking that a smaller tank will be less work to keep clean. This may seem logical, but it simply isn't the case. A larger tank is more stable, can have a more balanced cycle of water-purifying bacteria, and can comfortably house certain fish species which will help you keep the tank clean (such as the plecostomus, or sucker-mouthed catfish). It also reduces the likelihood of fish crowding. Crowding will cause the water to get dirty faster and cause the fish to get sick more often. The most commonly sold aquarium size is ten gallons. I would recommend a tank of no less than 30 gallons in size; the bare minimum size needed to adequately keep many popular species of fish such as angelfish.
The second mistake people make when starting out is to get goldfish. They're popular, they're pretty, and they're rather tough, but they are a messy fish with a large metabolism. They eat a lot, and produce a lot of waste. When calculating fish density, I count a goldfish as being equal to three other fish the same size. There's nothing wrong with goldfish, mind you, but they do require considerably more maintenance than other fish.
The third mistake to avoid is setting your tank up near a window or other bright light source. Algae requires three things to grow; water, light, and nutrients. Water is a given since it is an aquarium. Nutrients are unavoidable; they are brought in with the fish, through the food they eat and the waste they expel. With an ample supply of both water and nutrients, it is important to keep the amount of light low to prevent copious amounts of algae from growing in your tank.
The fourth mistake which is easy to fall for is to use inadequate or improper filtration. Air pumps are not adequate to power a filter. If you choose to use an under-gravel filter, the filter should be run with a powerhead; a submersible magnetically driven water pump. A great way to keep maintenance down is to have both an under-gravel filter and a hang-on-back power filter operating on the same aquarium. The power filter hanging on the back of the tank is easy to maintain; simply pull the filter pad out, throw it away, and drop a new one in place. With this sort of a combination running, you should only need to clean the under-gravel filter every couple of months.
The fifth mistake on the not-to-do list, is to put the aquarium in a position that is difficult to access. Cleaning an aquarium on top of the bookshelf which requires a step stool to reach is going to make your chore much less pleasant. Putting it in the room furthest from a drain or water source will make water changes extra tedious. Don't put it someplace without adequate headroom for cleaning, and if possible keep it near a working drain and faucet.
Sixth on the list of common mistakes is overstocking the tank. This should probably be first on the list, because it is the most common mistake I see people make. Somewhere, sometime, someone came up with the "inch of fish per gallon of tank size" rule and it has stuck. This rule causes many problems. The biggest problem is that fish are sold when they are still young and small. That inch-long silver dollar fish may grow to 4 inches in size. I've often seen pet stores selling juvenile pangasius catfish that sure look cute at only two and a half inches, but some species of pangasius can reach up to 3 meters in length in the wild! Always check to find out what the full-grown size is before you buy a fish. Overstocking the tank will cause the fish to get sick and die, will cause the water quality to get bad, and will make the aquarium a maintenance nightmare. Make things easier for yourself; be conservative and go with 3/4 inch of fish for every gallon instead.
And for number seven we have overfeeding. Fish need only to be fed once per day, twice at most, only what they will eat completely within one minute. If there is leftover food after one minute, then you need to cut down the amount you are feeding. Fish always act hungry; it's their instinct to always look for food. Their entire life is spent looking for food, waiting for the opportunity to spawn, and watching out for bigger fish. That's pretty much all they know how to do. Just because they look hungry doesn't mean that they are not getting enough to eat.
Okay, those are seven things to avoid. Now here are some additional things you should do to help ensure that your new tank remains a welcome guest in your home.
Get a cleanup crew; there are fish and other creatures which will help you keep your tank looking cleaner longer. The most famous of these is the plecostomus catfish. It will eat algae from tank surfaces, especially the growing young fish. It will get large eventually, so you may end up trading it in at your local pet store for a smaller one some day. Other fish which don't get so big are a little harder to find but include the farlowella catfish and the otocinclus catfish. Platies, mollies, and gouramis are among other fish that will also browse on algae, though less effectively. Besides fish, a couple of apple snails (mystery snails) can do a bit of cleanup. Be sure to add them in as well when calculating the fish capacity in the tank.
Keep the aquarium lights on for no more than 8 hours a day. Lights left on too long will encourage a lot more algae to grow.
Use chemical-removing media in the filter. Activated carbon is the most commonly used for this purpose, and there are others which can be combined with it to remove things that carbon can't.
If all of these suggestions are followed to the letter, then you will find that keeping an aquarium need not be a hassle. Your tank will look great and stay clean longer, and it will be easier to clean when needed.