Welcome to the Fans of Disney's Finding Nemo

By Marc Levenson aka melev

After enjoying the recent Disney movie, Finding Nemo, many family members now find themselves yearning for their very own clownfish or tang. With a little information, your family can have beautiful marine fish that will live for many years to come. However, it’s important to realize that keeping marine fish is more complicated than buying a kitten, a hamster, or a goldfish. Hopefully, this small and brief list of important things to consider when setting up a saltwater aquarium will help in your endeavors.

Tank Size Does Matter

Even though you may have found a small fish, it needs room to grow and to roam about. A clownfish can be happy in a 10 gallon tank, but a 20 or 29 gallon tank will allow more creatures to be added in the future, possibly resulting in a beautiful “piece of the ocean” in your home. Tangs are herbivores, and need a lot of room to swim. A bare minimum tank size for this fish, when just a juvenile, is a 55 gallon aquarium. Some species of tangs need a 75 gallon, or even a 125 gallon! Tangs love to swim long distances quickly, and to put them in a smaller environment will cause them stress, and they can die from stress-related illnesses (such as “Ich”).

Type of Water

To help avoid nuisance algaes growing in the tank, reverse osmosis de-ionized water is recommended. This kind of water can often be purchased at the fish store where you found your saltwater pet.  Reverse osmosis (RO) water may also be purchased at a supermarket, as well as distilled water. Avoid the convenient temptation to use unfiltered tap water from the sink. It contains elements that are detrimental to a saltwater tank. Chlorine, phosphate, nitrate, fluoride and other noxious chemicals are readily detectable in tap water.  A successful saltwater tank needs pure water to keep the fish healthy.

Salt

Marine salt is readily available at most pet supplies, and Instant Ocean is both very popular and easy to find. When setting up a new tank, or when performing water changes, always mix the salt in water before adding it to the tank. A hydrometer, which gives you a “salinity reading” to mix the salt to the correct level, is a very important tool. To initially gauge mixing, use ½ cup of salt per gallon of water, but test it with the hydrometer. Ideally, the salt level should test out with a specific gravity of 1.026 (35 ppt), and the water’s temperature at that reading should be 78 degrees. As water evaporates from the tank, you only need to add new RO or distilled water, because only water is evaporating from the tank. The salt is still there and will tend to increase over time. Adding more saltwater would only increase the salinity of the tank and eventually cause problems for the fish because the water would become too saline.

Heater

A successful marine tank needs to have a stable temperature. 76° F to 84° F is an allowable tolerance. Keeping it between 78-82° F is ideal. A small reliable heater will keep the tank from cooling too much at night (especially during winter). Likewise, a small fan blowing across the top of the tank will help avoid overheating during the summer months.

Food

Many marine fish will eat flake food, which is easily found at the local fish store. Frozen foods may also be purchased at the fish store to feed the fish. Remember, tangs are herbivores, although they will eat meaty foods, they need algae-based foods. Frozen spirulina-enriched brine shrimp, frozen Mysis, frozen blood worms and frozen plankton are all good choices, and it’s advisable to rotate through varied offerings of these over the period of a week, mixing their diet nicely. These foods come in small trays, frozen in cubes. One thawed cube is sufficient for a few fish, so avoid overfeeding. As a rule of thumb all the food should be consumed within five minutes. If you see food after that, you’ve fed too much. For most fish feeding once a day is enough, unless you have a tang. For these fish feeding twice a day is better, as they graze all day long in the wild. A good choice for feeding tangs is “Nori,” which is dried seaweed that can be clipped inside the tank and from which the tang will readily rip off pieces.

Lighting

Most tanks come with a single “normal output” fluorescent bulb, which is sufficient for fish. If a greater variety of inhabitants is desired, such as corals or anemones, far more lighting will be needed to allow them to thrive, let alone survive. When you get to that point, then your options will be VHO (Very High Output), PC (Power Compacts), or MH (Metal Halide) bulbs. These will be very costly, but the tank inhabitants will respond with healthy growth. These lights are not necessary for tanks with a few fish, however. Buy a simple 24 hour timer to plug in the lights, so they run about 10-12 hours a day.

Water Tests

Most important of all, saltwater tanks must be tested weekly to make sure the water is healthy so the fish will remain healthy. For a simple fish-only tank, it’s advisable to test pH, ammonia, nitrite, and nitrate. The tank’s pH should test around 8.0 to 8.3. Ammonia should read 0 before adding any fish, and so should  the system’s nitrite levels. Nitrate should be 20 ppm or less, and one of the best ways to keep these parameters down is by performing regular water changes. Another important test is alkalinity, which tests the water’s relative hardness. Ideally, this should be between 8 and 11 dKH. Also, be sure to double-check the specific gravity (salinity) weekly to make sure it has remained stable at 1.026 (35 ppt).

Filtration

The options in this category can vary quite a bit, but many like to use “hang on tank” filters. Just make sure the filter will match the tank size you’ve chosen. Placing a tiny filter on a 55 gallon aquarium is not a wise decision. Many people in the saltwater hobby prefer natural methods of filtration, which involves the use of “live sand” and “live rock.” Putting 4” of aragonite sand in the aquarium will create a great natural way of de-nitrifying your tank, which keeps the nitrates down. Buying cured live rock is also extremely valuable, but costs are high. 1 to 1.5 lbs. per gallon is recommended, and cured live rock will cost between $6 and $8 a pound! However, the live rock will be filled with tiny creatures, featherdusters, worms and more that all help consume the waste that occurs in your tank, keeping the system clean and healthy.

Protein Skimming

This is a fail-safe way of keeping the system’s water clean and pure. There are many types of protein skimmers on the market, and while some are great others are quite worthless. Two highly regarded ones are made by Aqua C and EuroReef. For a small aquarium, the Aqua C Remora will do a good job of pulling out waste before it can decay into ammonia and nitrites, which are both toxic to the fish. For a larger tank, like a 55 gallon housing a tang, you could get the Aqua C Remora Pro. What the skimmer does is inject air into a column of water in the unit, which creates tiny micro bubbles that carry Dissolved Organic Compounds (DOC) out of the tank and into a collection cup which can be poured out and rinsed quite easily. An added benefit of this device is that it adds oxygen to the tank. Unlike what is typically seen in freshwater tanks, saltwater tanks don’t need an airstone pumping bubbles into the tank. Typically, a good skimmer will cost between $150 and $200.

Circulation

Using a few power heads in the tank will move water throughout the tank. If efforts are made to avoid “dead” zones in your tank, nuisance algae will be less likely to grow. Cyanobacteria, for example, tends to grow in areas that are stagnant. Pointing the output of a powerhead toward the surface of your tank to cause the water to ripple will help create good gas exchange. This means oxygen will get into the water, and carbon dioxide will be released. This also keeps  the water surface nice and clean, and helps to avoid stagnant water or an oil-like scum from accumulating.

Cycling the Tank

Unlike a freshwater tank, it takes time for a saltwater tank to be ready for new fish or other creatures. Once the tank has been set up, you’ve added your sand, filled it with saltwater, turned on the heater and started the filters, then you can add the live rock. What the tank needs at this point is bacteria, and it needs to reproduce and spread before your new pets are added. A very easy way to do this is to buy one or two uncooked cocktail shrimp from the deli at the supermarket. Just throw them in the tank and let them rot. As they do, bacteria will grow as a result. Ammonia levels will rise in the tank over the period of a week to 10 days, then it will suddenly drop (observe this with your ammonia test kit), and nitrites will rise quickly over a period of another few days. Finally, the nitrites will drop off completely (reading 0 on the nitrites test), and nitrates will begin to register on your nitrates test kit. As soon as the ammonia and nitrites tests both read 0 on the matching test kits, it is safe to add the new fish.

Patience

As fish are added to the tank, the biological load in your tank is increased. It can only accept so much at one time, so it is far better to add new things very slowly to your tank, rather than all at once. That way the beneficial bacteria in the tank can increase to handle the new load and not create a sudden ammonia spike in your tank. By adding things slowly, the tank, the water, and the natural filtration will adjust for the new load. Remember, a new pet will require you to feed a little more, and that fish will add waste for the tank to absorb, and your natural filtration will need to keep up.

Janitors

Adding a few snails and small hermit crabs will help keep the tank clean. The snails will eat algae that grows on the glass or rocks, as will the hermit crabs. They also will consume excess food and waste that accumulates in the tank, thereby helping to keep things clean. Please do not add these janitors until the tank has fully cycled. If you see a snail that is upside down on the floor (or substrate) of your tank, take the time to flip it back over, or a hermit crab will eat it and adopt the shell as its new home.

Caution When Handling

Make sure your hands and your equipment are clean. Never put your hands in your tank if they have soap or hand lotion on them. Never clean any equipment with soap. Buy a new sponge that does not have “anti-mildew” additives, and keep it with your saltwater stuff, where it never will be used with soap accidentally. Often, many things can be cleaned with a mixture of common white vinegar and hot water, to remove calcium deposits.

There is much more to learn as you become more familiar with your aquarium and its needs. This is just a brief overview to help you quickly see what is involved. Many of the members of Reef Central endeavor to help everyone that wants to have a marine tank in their home. So come back often, and be sure to check out the discussion forums. Over 30,000 members access Reef Central to gain more knowledge and improve their own success rate with their tanks. Ask questions, use the “search” option, and read as much as you can, and you too can be successful.

For a more detailed look into the requirements of these animals, please check the following articles by Henry C. Schultz III in Reefkeeping Online.

Blue Tang - Identity Crisis – What's My Name? Paracanthurus hepatus

Clownfish - Time to Quit Clownin' Around: The Subfamily Amphiprioninae