Basic Aquarium Equipment

Tons of aquarium gadgets are available at pet stores. Some are essential while others are useful only for specialized applications. The following checklist shows the items that will likely to be of use to you.

Aquarium Tanks

Tanks come in many shapes and sizes, but there are only two types: glass and acrylic. Glass tanks are the cheapest and more easily to come by in India. Following is a comparison between the two:

Cheapest per gallon More expensive per gallon
Hard to scratch [Easy to scrape algae away] Scratches easily [Difficult to scrape algae away]
Scratches permanent Scratches permanent
Higher index of refraction [Distorts more when viewed from angle] Lower index of refraction [Distorts less when viewed from angle]
Empty tank heavier [especially when tank is larger than 30 gallons] Same sized empty tank weighs less
Tank stand only needs to support edges Special stand needed that supports entire base of tank and not just edges
Breaks easily Harder to break

The size and shape of the tank is completely up to you. However, keep the following in mind:

  1. Contrary to first impressions, larger tanks are not necessarily more work than smaller ones. In particular, it is easier to keep water chemistry stable in larger tanks than in smaller ones (the less water, the more easily a small chemical change causes a big change in relative concentration).
  2. Much of the regular maintenance work does not require twice the time for twice the size. For example, regular partial water changes for a larger tank may require at the most one more bucket of water than for a small tank. That doesn't translate into twice the work.
  3. It is very common for people to really like their fish tank and want to add more fish. A larger tank can hold more fish safely. Indeed, a single 10gallon tank adequately supports only a handful of medium sized fish.
  4. The number of fish that a tank can safely hold depends not only on the volume of the tank, but also on its shape. For example, some fish spend their entire lives near the bottom. Doubling the volume of a tank by doubling its height won't allow you to keep more bottom dwelling fish. Surface area is more important than volume in determining how many fish a tank can support.
  5. If possible, start with at 20gallon (or larger) tank rather than a 10gallon (or smaller) one. A 20gallon ("high" or "tall") aquarium makes an excellent first tank size. Avoid all tanks smaller than 10gallon. They are simply too small to keep healthy.


If you are keeping tropical fish, you will need a heater. A heater insures that a tank doesn't get too cool, and that the temperature stays steady during the course of the day, even when the room cools off (e.g. at night). For many tropical fish, a temperature of 78F is ideal.

There are two main types of heaters - submersible and partially submersible. Submersible heaters stay completely below the water. A second, more traditional style, has a partially submerged glass tube (which contains the heating coils), but leaves the controls above the water. Submersible heaters are the better design, as they can be placed horizontally along the tank's bottom. This helps keep tank temperature uniform and prevents the heater from becoming exposed while doing partial water changes. With the traditional design, one must remember to unplug the heater before doing water changes. If the heater is accidentally left on while the coil is above the water, the tube will get hot and may crack when you fill the tank back up with water.

If your room is never more than 8-10F degrees cooler than your target tank temperature, a heater of roughly 2.5 Watts per gallon will suffice. If the differential is higher, up to 5 Watts (or more) per gallon may be necessary. Remember, the heater needs to keep the tank at its target temperature, even when the room is at its coldest point; the tank's temperature should not fluctuate.

Heaters (especially cheap ones) will fail. Most often the contact that actually turns the heater on and off gets permanently stuck, either in the on or off position. In the former case, your tank can get very hot, especially if the heater is larger than your tank actually requires. To minimize potential problems, avoid heaters larger than the optimal size for your tank. To prevent winter disasters, use two smaller heaters in parallel rather than one large one. That way if one fails, the consequences won't be as disastrous.


You will need a thermometer to verify that your tank stays at its proper temperature. Two types are commonly available. The traditional bulb thermometer works the same way as the ones you can buy for your house. They either hang from the top edge of your tank, or float along the surface. The second common design is a flat model that sticks to the outside of the glass. In this design, liquid crystals activate at a specific temperature, either highlighting the numerical temperature or a bar that slides along a scale.


There are three types of filtration: biological, mechanical and chemical. Biological filtration decomposes the toxic ammonia that fish produce as waste products. All fish tanks must have biological filtration. Biological filtration is the cheapest, most efficient and most stable way to breakdown toxic ammonia. Mechanical filtration traps such particles as plant leaves, uneaten food, etc. (collectively known as mulm), allowing them to be removed from the tank before they decompose into ammonia. Chemical filtration (e.g. activated carbon, Zeolite, etc.) can remove (under limited circumstances) such substances as ammonia, heavy metals, dissolved organics, etc. through chemistry (e.g. adsorbtion or ion-exchange resins). Chemical filtration is mostly useful for dealing with short-term problems, such as removing medications after they've served their purpose, or purifying tap water before it goes into a tank. A healthy tank does not require the use of chemical filters such as activated

One point about filtration cannot be made enough. All fish tanks must have biological filtration. Although chemical filtration can remove ammonia under limited circumstances, it is not a general solution.

Filters are not maintenance-free. For example, if debris is allowed to accumulate in a mechanical filter, it decomposes into ammonia, negating its primary purpose. Likewise, a biological filter's effectiveness diminishes as it becomes clogged. Biological filtration requires water movement across a large surface area on which bacteria have attached (e.g. floss or gravel). The lesser the surface area available, the less effective the filter. Under Gravel Filters (UGFs) are cleaned by regularly vacuuming the gravel (e.g. while doing partial water changes). Canister and power filters are cleaned by removing the media and gently squeezing it in a bucket of tank water.


Gravel serves three main purposes. First, it serves as decoration, making your tank look nicer. Second, if using an UGF, gravel is mandatory as it is the filter media (the surface area on which bacteria attach). Third, in tanks with plant, it serves as a substrate (e.g. dirt) for plant roots. The choice of color, size, etc. is up to you. However, be aware that a fish's colors are highlighted well by dark gravel. Fishes adjust their colors to match that of the surroundings, and light gravel tends to wash out a fish's true colors. Alternatively, sand can also be used.

Be aware that not all gravel is inert. For example, coral, seashells, dolomite and limestone will release (leach) carbonates into the tank raising its pH buffering capacity. As a quick test, drip an acid (e.g., vinegar) onto the gravel in question. If it foams or bubbles, the gravel is going to leach carbonates into the water. To be absolutely sure, fill a bucket of gravel with water and measure the pH over a period of a week. If the pH remains stable, it should be safe to use in your tank.

When used for the first time, gravel should be washed thoroughly. Simply rinse clean water through it until the water comes out clear (tap water is fine). For example, put the gravel in a bucket of water, fill it with water, and churn the gravel up. Drain the water and repeat the procedure until the water remains clear. Before using gravel of unknown origin (e.g. when not purchased at a fish store), you may (as a precaution) want to boil it for 15 minutes to kill unwanted bacteria.

Driftwood and other Decorations

It is safe to place items in your tank as long as they are inert, meaning they won't release (leach) chemicals into the water. Most plastics are inert, as are glass and ceramic.

Wood may leach substances into the water, changing the pH in a possibly inappropriate manner. Driftwood often leaches tannins and other humic acids into the water (much like peat moss), possibly softening it and lowering its pH. The water may also obtain a yellowish tea-colored tint. The tint is not harmful and can be removed by filtering the water through activated charcoal.

If you use wood that you've found yourself (e.g. in woods or a lake), boil it first to kill any pathogens. Boiling it (long enough) will also make it sink in a tank.

Lights & Hood

It is important to purchase lights and a hood. A hood prevents fish from jumping out of the tank and reduces the rate at which water evaporates. A good hood effectively seals the tank. You want as little water as possible evaporating as it may raise the room's humidity to unacceptable levels and require more maintenance (i.e., you will have to top off the tank once or twice a week to replace the lost water).

There are two styles of hoods. Full hoods combine the light and hood as a single unit. Hoods include space for only 1 or 2 (parallel) fluorescent light tubes, which is fine for fish-only tanks, but not usually enough for growing plants. Glass / Tin canopies cover the tank with two strips of glass / tin, but don't include lighting. A separate light is used in conjunction with it. Canopies are a bit better for plant tanks than full hoods; since one can upgrade or change the lighting without replacing the entire hood, and in situations where very high wattage is needed, one can usually fit more light tubes directly above the tank.

Light serves two purposes. It highlights and shows off your fish's colors and provides (critical) energy for plants (if present). Unfortunately, the two purposes conflict somewhat. In a fish-only tank, a single low-wattage fluorescent bulb suffices and does a good job of showing a fish's true colors (as most fish don't like bright lights). If you want to grow plants, however, more light is needed, and the bulb's spectrum becomes an issue.

Whether or not you will be growing plants, fluorescent lights are the best source of light. Incandescent bulbs give off too much heat, causing your tank to overheat in the summer. Fluorescent bulbs run cooler and use less electricity for the same amount of light. Though in the summers, even fluorescent lighting can produce enough heat to lead to tank overheating problems, if your house gets warm or if you live in the tropics and don't have air conditioning.

Unfortunately, light grows not only plants, but also algae. If your tank contains abundant light, which only plants desire and there are no plants, algae will quickly fill the void. Thus, the ideal lighting for fish-only tanks differs significantly from that for a plant tank. Two components of light are of particular importance: intensity (i.e., wattage) and spectrum. Plants require intense light and certain spectral ranges produce more growth than others.


A powerhead is a water pump that runs completely submerged in a tank. They typically attach to the "lift tubes" associated with UGF filters, pulling water through the lift tube. The stream of outgoing water can usually be oriented in (almost) any direction, and it is common to point them in such a way that water circulates throughout the tank and stirs up or "agitates" the surface a bit.

Air Pumps

An air pump simply bubbles air through your tank. Air pumps serve two purposes. First, they insure that your tank maintains an adequate concentration of oxygen. An air pump is not required for this purpose, as long as your tank maintains adequate water movement together with surface agitation. This is generally the case if external (e.g. box or canister) filters are used. Second, air pumps can be used to force water through a filter (e.g. sponge or corner filter). If using a UGF, for example, an air pump produces bubbles that force water up the uplift tubes, pulling water through the filter. In larger tanks, powerheads perform the same function. Thus, an air pump is not required, provided your tank has good water circulation.


You will need some sort of a stand to place your tank on. The stand can either be specially designed to hold your tank, or some existing furniture. The first thing to consider is whether your chosen stand can support the tank's weight. When full of water, tanks weigh a lot (the water alone weighs roughly 10 lbs/gallon).

Stands should keep the tank level, in order to keep weight distributed properly. An un-level tank places stress in the wrong places, increasing the odds of having the tank break. In order to more evenly distribute weight on the stand, it is a good idea to place a 1/4-inch sheet of thermacoal between the stand and the tank.


There are two kinds of plants used in aquariums - real and plastic. Both kinds provide decoration and hiding places for fish. Plastic plants are (obviously) easier to maintain. Although it is possible to grow real plants in an aquarium, it is not always easy to do so (e.g. plants have special lighting requirements).

Bucket For Water Changes

You will need at least one bucket for adding and removing water from your tank. Use the largest bucket you can comfortably work with (e.g. up to 5 gallons). Use it only for your aquarium and don't ever put any chemicals in it.


You will need at least one fish net, and having two is better; catching fish is easier if you use one net to chase fish into the other. Nets with a fine mesh are harder to use because of their high water resistance. The right net size will of course depend on the size of your fish.

Netting fishes is stressful. In particular, the fish net scrapes off some of a fish's protective slime coating. If possible, when catching fish, use a net to chase the fish into a small plastic or glass jar.

Test Kits

You will probably want to buy some test kits for measuring things like ammonia concentrations, pH value.

Miscellaneous Cleaning Tools

Siphoning is the easiest way to remove water from a tank. For large tanks, using a long hose allows one to dispense with the bucket and allows you to siphon water directly into a drain or outside garden. When removing water via siphoning, you should also clean (vacuum) your gravel. Many water-changing hoses are available at local fish stores and include a gravel cleaning attachment. The basic idea behind them is to connect a wide mouthed tube to the end of the siphon hose. When the tube is plunged into the gravel, the water flow churns up the gravel, but only the detritus (dirt, mulm, etc) is light enough to be siphoned out.

To remove algae from the side of your tank, a plastic, non-soapy scouring pad can be used. If you have an acrylic tank, be especially careful that the pad isn't hard enough to scratch the side.

Some of the slower growing algae simply can't be removed with a scouring pad without a lot of work (and churning of the tank!). A razor blade works best at this point. A razor blade can be used to remove just about anything from the sides of a tank. However, razor blades can scratch glass, if one is not careful.

So-called "magnet cleaners" can also be helpful for removing algae. A scraping block on the inside of the tank is held in place by a magnet held on the outside of the tank. Moving the outside magnet moves the scraping block, removing algae without having to plunge your entire arm in the tank. The best magnet cleaners are those with a strong magnetic field (e.g. larger magnets), and they work best on smaller tanks, which have thinner glass.