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Building Atlantis From the Gravel Up

Fish are not only beautiful, serene companions, but setting up and maintaining your very own fish city can be an enjoyable and creative activity. Think about it-when else would you really have a chance in your lifetime to envision, create and sustain a whole living, breathing world!

In order to help you become a successful Master of Atlantis, senior aquarist Frank Greco of the New York Aquarium in Coney Island offers great advice from the gravel up.

How to Keep Fish in the Tank and Out Of the Stereo

First, decide where you want to put your fish tank. Water weights bout 8.3 pounds per gallon. A completely set-up 30 gallon aquarium, including gravel, decorations, and water, can weight up to 250 pounds. The larger the tank, the more weight you'll have to deal with.

tropical fish

The weight factor makes it highly important that you give much thought to not only where you place the aquarium, but on what. Greco says most homes should be able to support the weight of aquariums up to 75 gallons without additional support. "In any event, it is always best to place a tank along a wall, where floor supports are usually greater, rather than in the middle of a room," he says. You also want to avoid putting the tank too close to a window or heat source. Placing a tank too close to a sunny window may encourage the growth of undesirable algae and throw off the temperature of the whole tank. The same goes for too-close heating systems. You don't want to put the tank too close to that old-fashioned radiator in your pre-war apartment, for example. "Placing your tank too close to a heat source may cause the tank temperature to fluctuate wildly or to overheat, with dire results to the inhabitants at worst," he says.

Filters heaters and lights all require electricity, which means your tank has to be near an outlet. "It is of the utmost importance that electrical service is located close enough to the tank so the extension cords are not used," Greco says. "If you must use an extension cord, make sure it is ground fault protected. It is also important to provide a drip loop so that on the outside chance of water dripping down a wire, it will fall to the floor rather than into the electrical outlet."

Once you've got a spot, start thinking about a tank stand. Greco suggests going for quality and durability when choosing this piece, which he calls "the workhorse of the aquarium hobby." Don't skimp on this important foundation, and stay away from particleboard and TV-type stands. "These types of stands expand and weaken when they get wet," Greco says, "and then the fish tank is in the stereo."

Water Conditions

"Don't go cheap on the filter," Greco advises. Out are the old "box type" filters; in are the new self-contained units. "The newest filters use cartridges that you can throw away when they get dirty, making them much easier to maintain." Some of the newest tanks, like the Eclipse line from Marine Land, have both the filter and the heater built right into the hood of the tank, making them especially well-suited for the junior hobbyist. Greco also advises staying away from 'under-gravel' filters, which he says require lots of maintenance and tend to mess up water quality in the tank.

Invest in a good, submersible well-sealed heater. "The old rule of thumb of 5 watts per gallon may hold in a room where the average temperature never falls below 70 degrees Fahrenheit," Greco says. "In an area where the ambient temperature may drop, seven watts per gallon or greater may be what is needed to maintain a steady temperature." Also, it's a good idea to put your tank's thermostat on the opposite side of where the heater is to make sure you're getting an accurate tank temperature reading.

The type of lighting you will need depends on whether or not you will be adding live plants to the tank. If you're sticking with plastic plants, a simple single bulb fluorescent strip light should do. Live plants require a double fluorescent fixture. For even better plant growth, Greco suggests "very high output" (VHO) or power compact fluorescent lighting.

Python Products

Let There Be Life!

You've got the fundamentals in place. Now the real fun can begin!

Decorating a fish tank is like decorating your own world, but you have to see it from a fish-eye view. First, start with the gravel. Greco likes to stick with natural stone colors, but there are countless varieties out there. Glass and marble, however, are not the best gravel choices. "Bottom dwellers can get their whiskers torn up on glass gravel," Greco says, "and marbles can trap dirt and make the water quality go quickly downhill." Whatever gravel you choose, rinse it off well and pour it in dry to the bottom of a clean, dry tank until it fills up about 2-3 inches deep. Generally, you should use 1 to 1 1/2 pounds of gravel per five gallons of tank.

Once the gravel is in place, add any rocks, driftwood or other decorations. Try to place these materials so that they not only create a scene pleasing to the eye, but that also provides hiding places for the fish. Make sure that whatever materials you use are aquarium safe. That nice looking rock you picked up on vacation, or the oddly shaped piece of driftwood you picked up along the beach may look nice but may also be hazardous to your fish. Whatever decorations you use make sure they are placed securely. There's nothing worse that setting up a tank, only to have the aquascape collapse due to improper placement.

Next, decide on how you're going to get water into the tank, and remember that this is the way you're going to have to do it from now on. "There is nothing messier than having to drag buckets of water from the tank to the sink and back again, and the closer to the sink, the better," Greco says. However, as most apartment dwellers know, this isn't always possible. "There are devices that will allow the placement of a tank within 100 feet of a sink. These devices, called gravel-cleaning siphons, allow you not only to gravel clean the tank while performing water changes, but also lets you refill the tank afterwards." The one he strongly recommends for New York City apartment dwellers who have to be creative with space is the Python No Spill Clean and Fill Aquarium Maintenance System. "This is one tool that should be found in every hobbyist's toolbox," the professional aquarist says.

Fill the aquarium approximately half way with conditioned tap water. This water should be of the proper temperature range, and dechlorinated either by the use of a slimy water conditioner or by allowing the water to sit, aerated, overnight.

Once the tank is party filled, you can add any plants, live or artificial. Plants should be placed so as to compliment other decorations, and to add a finishing touch to the aquascape. Once the plants are in place, CAREFULLY add the remainder of the water so as not to uproot the plants. If using live plants note that many species of barbs eat aquatic vegetation. It would be wise to ensure that the species you re considering do not fall into that category. Live plants to stay away from include Purple Crinkle, Dragon's Tongue and Underwater Pine, sometimes called Wood Fern.

At this point, you will want to install your outside power filter or canister filter, as well as a thermometer. Once the filters are in place, put the cover on the tank. There are two styles to choose from: a glass cover or a full hood. A glass cover is just that; two pieces of glass joined together by a hinge that covers the whole tank. You will need to add your own lighting if you go this route which is beneficial if you are using live plants since you can add more than one light strip. A full hood, on the other hand, is a one-piece plastic molded top. They usually come with a single bulb light fixture, although double bulb fixtures are available. No matter which manner of cover you chose, each would have a translucent plastic backstrip. This allows you to carefully cut portions out to allow for the passage of the filter and any wires or tubes running into the tank. Remember that some fish are jumpers, so do not make the cutouts any larger than they need to be.

Once everything is in place, plug in your heaters, filter and light. Allow the system to run for 24 hours, after which you will want to check the temperature to ensure the heater is working properly. If everything is in working order, you can then consider adding a few fish. Your newly setup tank may be cloudy for the first few days, or even a week. This is normal, and is nothing to be concerned with. This cloudiness will clear up on its own as the filter begins to do its job.

Finally, The Fish

At this point, there is always the temptation to add too many fish to a newly set up system. (Greco calls this the "just-one-more-fish" syndrome.) Fish should be added gradually, generally no more than one or two small to medium sized fish per 10 gallons. This will allow the tank to become biologically established without too much of an ammonia/nitrite spike that can be stressful or fatal to the fish. Once fish have been added, monitor water quality periodically, taking whatever corrective action is needed. Do not add any additional fish until the biological cycle has finished, generally three to four weeks.

Tank Tips:


Some driftwood may, at first, float. To get round this, you might try soaking it in a clean container of water until it is waterlogged or attach it to a rock base. If using a submersible heater, you should place it in the tank now. You will want to hide it from view while at the same time allowing for viewing of the on/off light. DO NOT bury the heater under the gravel as this may cause the glass tube to crack.

Plastic plants are easier to maintain than live plants, and you can't just put any old plant in the tank. "If it looks like a houseplant, it probably is," Greco says. Stay with the safe, specially made artificial plants if you can. A good rule of thumb: don't put it in if you don't know what it's made of.

When decorating the tank, give the fish some places they can hide.


Once the tank is filled up with water, but before putting any fish in, add one teaspoon of aquarium salt or kosher salt per gallon of water to help fish resist disease.

Good "starting fish" choices are Swordtails, Platys, Zebra Danios, Dwarf Barbs and Small Tetras. Goldfish and tropical fish shouldn't be mixed together. Catfish or other algae eaters (that big "sucker" fish you see stuck onto the inside of the tank in many pet stores is an algae-eater called Plecostomus) should be saved for later on one the life of the tank is established.

When choosing a fish, look for alert swimmers with good color. Signs of possible sickness include scratching along the bottom, white spots or shaking in a corner of the tank. There should be no sick or dead fish in the tank.

Most of the time you will bring the fish home in a plastic bag with some of the water from the tank you bought it from. Once you're home, open the top of the bag, fold it over like a cuff, and let it float on top of the tank for five or ten minutes. Use a net to put the fish in the tank and throw the bag water away. (If you've bought the fish from outside of the immediate area, it's okay to add a little bit of it's native water to the tank but dump the rest.)

Feed your fish two or three times a day only as much as they can eat in one minute. Flaked food is your best bet, with occasional treats.

Remember that old joke about whether fish sleep? Like you, they are on a regular 24-hour day schedule. Rather than keep them in the dark all day and then turn on their tank light when you get home, try to set a timer for it to go on a few hours before you get home and to turn off around the time you go to bed.

Once a month, take about 25 percent of the tank water out and replace it with fresh water.

These tips should keep your tank healthy and your Aqualand residents happy.

Frank M. Greco and Diane West

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