Check out our other tank kits from Marineland, perfect for your kid’s room or the office desk!
Check out our other tank kits from Marineland, perfect for your kid’s room or the office desk!
All organisms, whether animal, plant, or fungus, produce organic wastes, either during their lives as products of their metabolic activity (excreta, carbon dioxide, etc.) and the shedding of dead tissue (skin cells, leaves, etc.) or through the decay of the entire life form after death. These residues are recycled in nature via biogeochemical processes, one of which is the nitrogen cycle, which also takes place within the aquarium. The successful establishment of this cycle is fundamental for the long-term health of the aquarium and its inhabitants. Fortunately, there are bacterial strains that metabolize the waste products of aquarium life into relatively harmless gases, thereby allowing the aquarium to sustain life.
It can take anywhere from thirty to forty-five days for sufficient amounts of bacteria to grow to maintain the cycle. The first of these bacteria, nitrosomonas marina breaks down the primary waste product, ammonia (NH3) and converts it into nitrite (NO2). Nitrosomonas should begin to appear around Day 10 of the cycling process. The nitrite level will peak at 15ppm (parts per million) around Day 20, until the second and third bacterial strains appear. Nitrospira spp. and nitrobacter further the nitrogen cycle by metabolizing nitrite and converting it into nitrate (NO3). These bacteria should begin to make a significant impact around Day 25; when the level of nitrite should begin to fall off to less than 3ppm. As the nitrite level decreases, the nitrate level will steadily rise and once it reaches 10ppm, the aquarium has been fully cycled. There is no bacterial strain that can break down nitrate; subsequently the level of nitrate will keep rising, unless it is removed. Although plants, algae, and anaerobic bacteria may use it as nutriment, the majority will remain and must be removed by regular water changes.
The nitrogen cycle will initiate once the nitrifying bacteria have a source of ammonia. There are two ways to introduce ammonia into the aquarium, one is by introducing fish, and the other is by fishless cycling.
Another way to expedite the nitrogen cycle is to increase the supply of nitrifying bacteria. Good sources of these beneficial bacteria include: filter material, gravel, ornaments, and live plants from a preexisting aquarium since these objects already have large bacterial colonies residing on them. There are also commercial bacterial supplements (Stress Zyme, Bio-Spira, Cycle, etc.) available, which contain live bacteria to accelerate the cycle.
However none of these items will help if the aquarium does not meet the bacteria’s basic needs. Nitrosomonas, nitrospira, and nitrobacter require plenty of oxygen, ammonia, heat, surface areas, and low currents in order to flourish and sustain an adequate bioload.
During the fish cycling method, 10-30% water changes should be done every 4-5 days not only to avoid casualties, but also to prevent the prolonging of the cycle. It is a myth that performing water changes slows down the nitrogen cycle since the beneficial bacteria reside on the surfaces of gravel, tank walls, plants, and any other ornaments within the aquarium. In addition the pH and temperature of an aquarium factor into how often water changes are needed since ammonia is much more toxic in its unionized state (NH3) than in its ionized state, ammonium (NH4+). Testing for ammonia in an aquarium actually reveals the combination of ammonium and ammonia known as Total Ammonia Nitrogen (TAN). The difference in pH with the same TAN is significant; water with a temperature of 82°F, a pH of 7.0, and a TAN of 5ppm, only has 0.3ppm of ammonia, whereas water with a temperature of 82°F, a pH of 9.0, and a TAN of 5ppm, has 2.06ppm of ammonia, a lethal level.
Once the nitrogen cycle has been established, it also must be maintained in a relative equilibrium to prevent it from crashing. Nitrogen must be added to the system (through food) and as nitrates rise, water changes must be done to keep the delicate balance.
Keeping the appropriate biological load in an aquarium will also help maintain the cycle. This means not overstocking the aquarium, a ten-gallon aquarium should only house ten small fish at the most. The one-inch per gallon rule does not always apply; a ten-inch fish should not be kept in a ten-gallon tank.
The nitrogen cycle is the biological process that converts ammonia into less harmful compounds. This is done by beneficial nitrifying bacteria, which in large numbers can sustain the entire aquarium by itself. The two key elements in the nitrogen cycle are nitrifying bacteria and their source of food, ammonia. Both of which are absent
in a new aquarium, however in a matter of weeks there should be enough bacteria to support a large number of aquatic life. With continued assistance from the owner – in the form of water changes – the nitrogen cycle should pretty much maintain itself and the aquarium.
Proper nutrition is important for the long-term health of the fish and to bring out
their full, vibrant colors. Try to provide a balanced and varied diet that contains all the
protein, fatty acids, fat-soluble carotenoids, carbohydrates, vitamins, and minerals to
Different types of fishes require dissimilar feeding requirements. For our purposes
they will be categorized into predatory/prey species and subdivided into piscivores,
herbivores, omnivores, and limnivores.
If there is any remaining food left floating or that has sunk, they are being overfed; cut the amount of food in half. Overfeeding not only directly affects a fish’s health, it does so indirectly by decaying and thus harming the water quality.
Other signs of overfeeding are “mold” growing on the substrate, food being unattended to, and feces trailing a fish’s cloaca.
A goldfish’s diet should consist of special food with a lower protein and a higher carbohydrate content as the staple. To supplement this, they should also be fed blanched vegetables, beans, anacharis/elodea, oats, worms, etc.
Herbivores (Tangs, Silver Dollars, Surgeonfish) graze constantly and should be fed blanched¹ slices of fresh vegetables like zucchini, spinach, cucumbers, and peas as well as edible aquaria plants, spirulina flakes, and dried seaweed sheets.
Make sure the plants, vegetables, and seaweed sheets are anchored or clipped firmly so the fish can easily grip and tear them. Remove whatever remains after a couple of hours.
Limnivores (literally mud-eater) include loaches, catfish, and blennies. They will feed on algae, snails, and microorganisms that live within the substrate. They should be fed algae wafers, shrimp pellets, bloodworms, etc.
Plecostomus’ are limnivores and they require the presence of driftwood in their aquarium as they feed off the biofilm, which is a major component of their natural diet.
In addition the size, shape, and position of a fish’s mouth will determine where
and how it will eat.
Not all foods are created equally and to compensate for this a diverse diet must be given. A diet of live, frozen, and dry foods is sure to provide sufficient amounts of the nutrients needed to ensure maximum growth, health, energy, and color.
Some difficult species of fish like lionfish or voracious predators like piranha are fed feeder fish because either they will only eat live fish or the owner enjoys watching their pet eat how they would in nature. However, this form of feeding is doing them a disservice as these common fish (goldfish, minnows, guppies, etc.) are often: housed in crowded tanks, undernourished, and carriers of diseases. These are poor quality fish and should never be introduced into a stable, healthy ecosystem. The predator must be weaned off feeders and onto frozen since there are superior substitutes (frozen krill, silversides, beefheart, etc.) and
they are guaranteed to be disease-free. It is of the utmost importance to begin the weaning process while they are growing; it will be much more difficult to succeed once they reach adulthood.
If the trip is to last less than four days, don’t do anything. Fish have evolved in such a way that several days without food does little damage to their body. For trips lasting more than four days there are several options available.
¹Blanching is a cooking process wherein the item is plunged into boiling water for a brief
amount of time. Immediately after removing the item from the boiling water, it should be
plunged into a bowl of iced water. There are many positives to blanching, but aquarists
mainly do it to soften firm vegetables.
Water changes are a crucial part of fishkeeping. Over time, large amounts of waste, dissolved gases, debris, and algae will build up in the aquarium and must be removed by the owner. Neglecting to do so will not only leave the tank unsightly, but may also gravely affect the long-term health of the fish. Water changes prevent toxic build-ups of ammonia, nitrite, and nitrates. Since fish continually excrete these chemicals, harmful levels can rapidly accumulate; changing water essentially reduces the total amount of waste concentration.
Two factors determine how effective the water change will be: the regularity of the water change and the percentage of water changed each time. If weekly water changes of 20% cannot be done, then bi-weekly changes of 33% must be done.
Large (50% & up) and occasional water changes will shock the fish and may cause stress related diseases due to drastic water chemistry changes. In addition the aquarium’s nitrogen cycle may become offset.
Equipment – algae pad, chemical–free bucket, thermometer, gravel vacuum, water conditioner, aquarium salt (optional)
It is recommended to replace 20% of the aquarium water every week to keep safe levels
of ammonia, nitrite, nitrates and phosphates.
1) Unplug or submerge the heater below the predicted water line.
2) Using the algae pad, scrub the sides of the aquarium to remove the algae.
3) Submerge the wide end of the gravel vacuum beneath the water and point the narrow end into the empty chemical-free bucket located below the aquarium. Start by shaking the wider end up and down rapidly, until the water starts draining into the bucket. While draining insert the wide end of the vacuum into the gravel and spot clean to remove trapped detritus. Some gravel vacuums are not equipped with a self-starting flapper and may require submerging the entire vacuum. If this is the case, submerge until all the air is void from the tubing and with one hand place your thumb over the narrow end and lead out of the aquarium and into the bucket; leave the wide end inside the tank.
4) Throw away the water or use it to water your garden, as it is an excellent fertilizer (freshwater only).
5) Prepare the replacement water by filling up a bucket & adding the proper amounts of conditioner and aquarium salt. The recommended dosage of aquarium salt for freshwater is ½ teaspoon per gallon. Mix the water thoroughly.
- Tap water can be used for freshwater/brackish tanks, but it requires a
water conditioner that removes and neutralizes the chlorine and
chloramines in it. If using RO/distilled water for freshwater many of the
useful minerals/electrolytes will be absent and should be replaced. For
marine tanks RO/distilled water is the best way to go, as the water will be
devoid of harmful substances like phosphate and copper.
- For saltwater/brackish aquariums, add marine salt and check the level of
salinity by means of a hydrometer. 1.022 g/mL at 75°F is optimum for
most saltwater tanks, 1.000 g/mL at 75°F is optimum for most brackish
- Aquarium salt while optional, is a useful treatment for sores, infections, parasites, and functions as a precautionary measure against disease organisms as it stimulates the fish’s production of slime coating.
6) Check that the prepared water is the same temperature as the aquarium water.
7) Pour the water in slowly and carefully as to not shock or scare your fish.
8) Occasionally rearrange large rocks, plants, or any decor to create new territories.
9) For the outside of the aquarium, a soft cloth dipped in water should do the job. For stubborn stains use vinegar or rubbing alcohol, as they are much safer than household glass cleaners.
10) Check levels of ammonia, nitrite, nitrate, and phosphate with test kit or at
Wilmette Pet Center to determine how effective water change was and frequency of future water changes.
11) Every 4-6 weeks replace the carbon package in the filter, check the effectiveness of the fluorescent lighting, heater, air pumps, etc. and replace accordingly.
- For planted substrates, do not disturb the plants as moving them will damage the roots, vacuum around them.
- For sand substrates, hold the gravel vacuum far enough that it won’t pick up the grains, but close enough that it will pick up any debris.
- For newly setup tanks 20% biweekly water changes will do as you want to promote beneficial bacteria and doing too many water changes will inhibit bacterial growth. During this critical period, water quality tests must be done weekly to be well informed of the development of the nitrogen cycle.
- For bowls and tanks of less than 5 gallons without a filter, 15% water changes every day is recommended.
- For breeding tanks up to one month old, 10% water changes every day should be done.
- Soap and other harsh chemicals must never be used to clean the tank or equipment. Unless the packaging explicitly states “aquarium safe”, do not use chemicals to aid in cleaning. Warm water and an algae pad should be used to clean the tank or equipment.
Old Tank Syndrome
OTS refers to when new fish are added to a fully mature tank (10–14 months after initial cycling is complete) with clear water and “healthy” fish, but die within 24 hours of being introduced. The problem is acidic water with a low pH and high nitrates. The drop in pH then affects the growth of beneficial bacteria, which then leads to a sharp increase in ammonia.
While the resident fish have slowly acclimated to the water conditions, the new fish could not handle the systemic shock of vastly different water conditions. The best way to remedy OTS is to return to weekly 20% water changes, add live plants to improve water quality, hold off on introducing any new inhabitants to the aquarium, and to routinely test water quality, particularly ammonia, nitrates, and pH.
Green Tank Syndrome
GTS is when algae overruns a tank and the water has a greenish/yellowish hue. The problem is a high level of nitrates and phosphates in the aquarium. Algae is not a bad thing in itself, since it absorbs nutrients, improving the water quality and it provides a source of food for some fish; however GTS is a problem as it indicates a lax attitude towards aquarium maintenance.
There are several things one can do to rid the aquarium of GTS; return to weekly 20% water changes, add live plants (since they compete with algae for the same nutrients), reduce the total time of light exposure, feed less food, routinely test water quality, or introduce algae-eating fish/snails.