Management of Water Quality in Aquarium

Water quality management in freshwater Aquariums

Dr. Subhendu Datta Senior Scientist

Water Chemistry: The Basics

Learning about water chemistry is often avoided by most aquarium owners, but by knowing just the basics of water chemistry, you can greatly improve your success in rearing healthy fish.

Most aquarium owners are aware that the quality of water

has a direct impact on the health of their fish. But many aquarium owners do not understand the basic internal chemistry of their fish's water, nor do they understand how to correctly or safely adjust it. Until the basics of water chemistry are mastered and some common water maintenance techniques are learned, it will be difficult to maintain a healthy and safe environment for the fish in your tank.

The water quality is by far the single most important factor in the health of your fish, and the more you know, the better job you will do. This article provides a brief overview that is just the bare minimum that aquarium owners should know and understand.

pH

Every aquarium owner has heard of pH, but many do not understand the importance of controlling it. pH is the measure of acidity or alkalinity in the water. The pH scale is from 1 to 14. A pH of 7 is neutral, which basically means the water is not acid or alkaline. As the scale goes down, for example 6, the water becomes more acidic. As the pH goes up, for example 8, the water gets more alkaline. One very important part of the pH scale that most people do not understand is that it is a logarithmic scale. What this means

Tap water is supplied for one purpose - human consumption. It is carefully screened, cleaned, treated with prophylactic chemicals and pumped into our homes for our use. It does not, however, carry a guarantee that it is suitable for fishkeeping. (Courtesy, The Encyclopedia of Tropical Aquarium Fish; Dick Mills and Dr. Gwynne Vevers; Tetra Press; page 24).

is that the pH changes at a tenfold level between each number. For example, a pH of 5 is 10 times more acidic than a pH of 6, and a pH of 4 is 100 times more acidic than a ph of 6. So if your fish are supposed to be at a pH of 7, and the water level is 8, they are in water that is 10 times more alkaline than what they should be. If the pH is 9, then they are in water that is 100 times more alkaline than what they need. So it is easy to see why even a small change in required pH is stressful and potentially fatal to fish.

These examples really emphasize the importance in matching your fish closely to the expected pH level of your water and then closely monitoring the pH. Putting a fish that requires a pH of 8 with a fish that requires a pH of 6 is just not a good idea because one or both will be at a very unacceptable level of pH and will be under a great deal of stress.

There are several different ways to influence your water's pH. There are chemical additives that can be added directly to the water that will either raise or lower the pH. More natural agents can be used to alter water pH as well. Peat in the tank or filter will acidify the water. Mineral salts like calcium that are found in limestone or in some shells will cause an increase in alkalinity and pH. There is one important consideration in altering the pH of water and that relates to the mineral content (hardness) of the water. See the section below for a complete description. Remember that fish are very sensitive to changes in pH, and rapid changes in pH can cause extreme stress and death. Fish should not be exposed to a change in pH greater than 0.3 in a 24-hour period.

Tap water is usually alkaline. Always test tap water pH prior to making freshwater aquarium water changes, and adjust as required. Marine aquaria should be maintained at a level of 8.2 to 8.4.

Temperature

While not considered chemistry, water temperature needs to be mentioned. Fish are cold blooded, which means they cannot raise or lower their body temperature and their body temperature will be the same as the water around them. If a fish is kept outside of their normal temperature range they will become stressed and become diseased or die. The majority of fish are tropical, which means they come from tropical climates with water temperatures around 75ºF. Even cold water species such as goldfish cannot handle very cold water or sudden changes in temperature. Know your species of fish and their temperature requirements.

Water hardness

Water hardness is often confusing and therefore overlooked by many aquarium owners. Water hardness is important because it is closely related to pH and, just like pH, fish have certain levels of water hardness that they thrive in, and if the hardness is too far off, it can cause stress and death. Water hardness can be most simply described as the level of mineral in the water. Hard water has a lot of dissolved mineral, and soft water has very little dissolved mineral in the water. The most common mineral in water is calcium, however, other minerals can also be present. Most people's tap water is either slightly hard or soft depending on where it comes from. Well water from areas that have a lot of limestone (calcium) is often hard. Water that comes from lakes (rainwater) is often devoid of mineral and is soft. It is important that you know the hardness of the water that you use in your fish tank. Some species of fish require hard water and others require soft water.

The other reason that hardness is important is that it affects pH. Hard water (high mineral content) is usually high in pH. Soft water (low mineral) is usually low in pH. The

mineral in hard water will act as a buffer which will reduce the amount of acid in the water. The resulting water will be more alkaline and higher in pH. The problem arises when we try to lower the pH in hard water. If we add a commercial pH decreaser to an aquarium that is filled with hard water, the mineral in the hard water will buffer the water and make it difficult to successfully lower the pH. We would first have to remove the mineral from the water before we could effectively lower the pH. The same is true for trying to raise the pH in acidic water that is soft and does not contain much mineral. Until we add mineral to the water, it will be difficult to successfully alter and maintain a high pH level. So what do we do? Well, it is not too hard to add mineral in the form of calcium based rock, so making soft water hard and more alkaline (higher in pH) should not be too difficult. To soften hard water, you need to take the mineral out with a water softener, reverse osmosis or a specialized chemical that irreversibly binds up the mineral. Another option is to find a source of demineralized water for your fish tank (rain water is soft in nature).

Of course the alternative to all of this may be to tailor your fish and plant species around your existing water source. For beginning aquarist this may be the best solution. There are a wide variety of tropical fish available and it is not difficult to find at least a dozen different species for every different type of water. Any decent book on aquariums and tropical fish will list the individual pH and hardness requirements of the different fish species.

If the water is too hard for your specific application (such as breeding certain species), simply mix it with deionized water until the required hardness is obtained. Most hobbyists don’t feel the need to measure this particular water quality.

Ammonia, nitrites, and nitrates

Ammonia, nitrites and nitrates are all part of the breakdown of waste in an aquarium. A significant amount of fish and plant waste can accumulate in any aquarium. Uneaten food, algae, and bacteria can also contribute to the waste load in an aquarium. As in all environments, this waste needs to be broken down and either eliminated or turned into something that can be utilized by another organism. In an aquarium there is a population of bacteria that is responsible for this process. The breakdown of waste is a four-part process.

1. First, the waste from fish, plants, and food breaks down and releases ammonia. 2. This ammonia is very toxic to fish and must be converted by bacteria to nitrite. 3. The nitrite is also toxic to fish and must then be converted to nitrate.

4. The nitrate is not nearly as toxic and is taken up by plants or algae and used to help them grow.

Ammonia is the most toxic product formed in water. Sources of ammonia in aquarium water are fish respiration and digestion and decaying foods. Freshwater fish begin to be stressed at levels of 0.50 ppm (parts per million). Marine aquaria levels should be less than 0.05 ppm.

Nitrate, nitrite, and ammonia are also removed through the weekly water changes. Because high levels of ammonia and nitrite are lethal for fish, it is critical that these products be efficiently removed or converted to nitrate.

Maintaining a population of bacteria that can convert ammonia and nitrite is an important part of the water chemistry, and the process is known as biological filtration. Biological filtration will occur

naturally in most tanks that have been up and running for a couple of months. The better filters often contain a special area or wheel that is made specifically for providing an optimal habitat for growing these bacteria. While the bacteria will live in a traditional filter and on rocks etc. in the aquarium, the new filters harbor a much higher number and can therefore do a better job of removing ammonia and nitrites.

If a fish tank is over crowded, or the waste level gets too high through overfeeding or dead fish etc., even a properly functioning biological filter can be overwhelmed and toxic conditions can result. Periodically checking the ammonia and nitrite levels in your tank with a test kit will ensure that your biological filter is working correctly. Tanks that have a healthy plant population will also aid in the removal of nitrates. Because it takes weeks to months for a tank to grow a healthy population of bacteria, it is important that a tank be allowed to age before fish are added. After the tank ages several weeks with only a few hardy fish, more fish can be slowly added over a couple of months to make sure the biological filter is not overloaded.

Nitrate

High levels of nitrate can be present in the water of wells contaminated from fertilizer, agricultural run off, or sewage. These nitrates are dangerous to humans as well as livestock. Nitrates can be removed by reverse osmosis or specialized nitrate removing chemicals.

Fig. Biofilter cycling over time Chlorine

Chlorine is commonly added to water supplies to disinfect the water (to kill bacteria) and can be harmful to fish. It is lethal to fish at 0.2 - 0.3 ppm. It can be removed with chemical chlorine eliminators or by aerating the water in a bucket over night.

Phosphates

Phosphate is a salt, commonly found in tap water, which serves as an algae nutrient. Maximum phosphate levels are 2 - 3 ppm with less than 0.05 ppm being ideal.

Reef tanks should be maintained at less than 0.05 ppm.

Importance of Water quality management in aquarium

Nothing is more important in aquarium keeping than water quality management. There are many excellent products available out there to assist in water quality management, but there is still no replacement for water changes, good filtration, and good feeding habits.

Water Changes: Changing water in more frequent, smaller amounts is preferable to larger less frequent changes. Make sure the water going in has the right chemistry (pH, etc.) and temperature. Weekly water changes are probably the most important part of maintaining good water quality. Weekly water changes of around 15%-20% of the total water volume will correct many potential problems in water quality. The water changes will bring fresh mineral rich water into the tank. The fish, plants and bacteria use up the trace minerals in the water and by adding new water weekly you replace these minerals. By removing water you reduce the amount of nitrate and ammonia that builds up in the water as well. Weekly water changes also help remove other toxins or pollutants that can build up in the tank. If a siphon with a gravel cleaner is used the gravel can be cleaned and uneaten food and fish and plant waste can also be removed. This keeps the ammonia levels down and the water cleaner. (If you have an under gravel filter or a filter system that does not have a biological filter you may not want to disrupt the good bacteria by over cleaning the gravel).

Remember that most tropical fish live in environments where currents or rainfall regularly bring fresh water and remove waste. By providing weekly water changes we help to simulate this natural and much needed requirement. An important note about water changes is to make sure the total does not exceed a third of the water volume. It is also important that the water that is added is free of chlorine. Otherwise use a declorinator (sodium thiosulfate), if chlorine or chloramines are present. (Wonder shells remove chlorine,

stabilize KH, and add electrolytes). Water changes are important for Nitrate removal and buildup of toxic organic and inorganic material. Filtration: Good filtration consists of biological, chemical, mechanical, and germicidal.

Biological: Biological filtration is the action of bacteria in the tank breaking down dangerous ammonia to nitrites and then the nitrites to the less toxic nitrates. Today most good new filters provide a separate area or wheel for the specific task of growing these necessary bacteria. These good nitrifying bacteria will grow in other places in the tank and on other filter media but not with as great a

numbers. It is hard to argue with the success of these new filters and their ease and success in providing high quality filtration. Regardless of which system you use to provide biological filtration, it is a very important part of maintaining the water quality. Remember that it takes weeks to properly grow the bacteria in a biological filter, so if you are setting up a new tank, wait several weeks before adding fish. At the same time be careful not to damage your existing biological filter with antibiotics, chemicals or over cleaning.

Sponge filters are excellent bio-filters (generally used in smaller aquariums, but there are larger ones now available, as well a sponge pre-filters for intakes of other filters), wet/dry on a larger scale, fluidized bed, and under gravel filters (Your canister filter, power filter, etc also can be biological filters- just make sure not to change all media during cleanings. You want to wash some of the media out in used aquarium water. Ceramic bio rings are excellent in canister filters for bio filtration). Live rock in marine aquariums also acts as bio filters. Chemical Filters - Chemical filtration is achieved by carbon and zeolite (freshwater only for zeolite).

Mechanical filtration is the removal of debris from the aquarium via filter floss, cartridges, ECT. Canister filters excel at mechanical filtration.

Germicidal filtration is the use of UV radiation or ozone to kill disease pathogens in the water. Good feeding habits simply means feeding what the fish will consume in 2-3 minutes (very general rule), twice per day. Also using a quality food that is highly digestible is very important for less waste (Spirulina 20 flake is excellent). Most fish foods available have too high of a cereal content and not enough fats and fish proteins.

Some more tips for Water Changes and Cleaning a Freshwater Aquarium

Regular changes are one of the most important aspects of maintaining good water quality. For live plant tanks, weekly changes are best to replace trace elements lost. In an unplanted freshwater aquarium, water parameters should be checked weekly with test kits, and water changes performed accordingly. Aquariums with a good filtration system, should have a monthly water change at the minimum, regardless of test results, generally to reduce the amount of nitrates in the water.

Here are 10 easy steps to efficiently clean your freshwater tank and perform a water change while reducing the stress on your fish.

1. Unplug the heater.

2. Remove any artificial plants and decorations, and clean all sides of the aquarium with an algae sponge.

3. Turn off the pump. Disconnect the filter and take it, along with the artificial plants and decorations, to a tub or sink.

4. Clean the filter, artificial plants, and decorations. During this time, any debris that was stirred up will settle in the tank.

5. Connect a gravel cleaner. This may be a siphon which attaches to a faucet, or a manual siphon used with a bucket to collect the water. Start the siphon and push the gravel cleaner into the gravel all the way to the bottom, and leave it there as debris rises into the siphon. Continue until the water starts to clear, then either pinch the tubing or partially close the valve to let the

gravel fall back down. Lift the gravel-cleaning tube out of the gravel and push it back down right next to the last section you just cleaned.

6. It's time to stop when you have removed 25-30% of the water (the water level drops to 3/4 to 2/3 of what it was before you started). If you did not get through cleaning all of the gravel, you can start where you left off with the next water change.

7. Take the temperature reading in the tank, then go to the sink and adjust the water temperature to match. This is a very important (but often overlooked) step. Adding water of a different temperature can unnecessarily stress the fish, making them more susceptible to diseases such as Itch.

8. Flip the faucet pump to run water into the aquarium, or fill a bucket and pour the water back into the tank to original levels. If using a faucet pump, while the tank is filling, add some de-chlorinator if you have chlorine in your water source. If you are using a bucket, add the de-chlorinator to the water before pouring it into the aquarium.

9. Replace your artificial plants and decorations and reconnect the filter. 10. Plug in the heater and restart the pump.

Ideal Water Parameters

Making sure your tank has all of the appropriate water parameters and environmental requirements a particular species needs is one way to assure your tank is healthy.

Parameters Ideal for breeding

For culture in Pond SL.

No.

Name of the fish Water Temperature (oC)

pH Water hardness (mg/L CaCO3)

Egg layers

1. Gold fish (winter breeder)

18 - 20 7-7.5 90-200

2. Koi carp (winter breeder)

20 - 22 7- 7.5 70 - 200

3. Angel (summer breeder) 22 – 32 (breeding) 28 – 30 (larval rearing) 6.3 – 8.5 70 - 200 4. Gourami (summer breeder) 24 - 30 6.0 – 7.0 60 - 100 Live bearers

5. Sowrd tail (-do-) 28-30 6.5 – 7.5 80 - 250

6. Platy (-do-) 28-30 6.5 – 7.5 80 - 250 7. Guppy (-do-) 28-30 6.5 – 7.5 80 - 250 8. Molly (-do-) 28-30 6.5 – 7.5 80 - 250 Parameters Range Temperature 18 - 37°C pH 6.5 - 7.5 Ammonia 0.0 Nitrite 0.0 Nitrate < 50 ppm Alkalinity (Carbonate Hardness) 70 - 150 ppm General Hardness 70 - 200 ppm

Other aspect of maintaining the water quality Setting up the tank correctly

Many problems with water quality start before we even add water to the fish tank. Most new tanks are well made and do not contain toxic materials in the caulk or general construction. The problems usually arise from the substrate and decorations that are added to the water. If you use gravel, rocks and wood from your yard or garden shop, be aware that you can be bringing contaminants into your tank. A common problem is when people put rocks or gravel of unknown origin into their tanks and the rocks contain limestone. The limestone will make the water more alkaline and the aquarium owner will constantly struggle with maintaining the proper pH in their tank. Setting up the tank with clean appropriate substrate, wood and rock is the first step in maintaining water quality.

Live plants

Whether or not to have live plants in an aquarium is often a personal choice and many aquariums do very well without ever having a live plant in them. However, live plants in a tank offer many advantages. While some live plants can be difficult to grow and may initially require a little more maintenance, the benefits to water quality and fish health are well worth it. Plants are great at absorbing carbon dioxide and nitrates and provide shelter and security for the fish. Because they compete with algae for nutrients they can also help reduce algae growth. Live plants also enhance the appearance and provide a much more natural environment for the fish. By improving water quality and reducing stress, live plants are a great way to improve your fish's health. Adding live plants does not reduce the need for weekly waters changes. When selecting live plants make sure to choose species that are truly submersible and that are suitable for your specific water type and fish species.

-CAUTION-

Adjustment and/or corrections to existing water chemistry MUST be made gradually.

Stability is as important as water quality.

A Canister filter is a large, powerful aquarium filter used for mechanical, biological and optionally, chemical filtration. Canister filters sit below the tank, usually inside of the aquarium stand. They are closed cylinders that stand about 15" (38 cm) high, with locking lids. The lids have intake and outtake valves that connect to tubing, which feeds up into the tank. The intake tube draws water into the filter where it follows a circuitous path through various filter mediums before being expelled at the outtake valve to return to the tank. Canister filters are extremely robust. Unlike hang on tank filters, canister filters can normally go several months without maintenance of any kind. The Carbon in canister filter absorbs dissolved organics, fish odors, toxic metals and growth inhibiting enzymes and provides biological reduction of ammonia to nitrate.

b

Kordon Amquel - Removes ammonia, chloramines, chlorine, and many other organic toxins. Completely non-toxic, contains no formaldehyde, and will not affect dissolved oxygen levels. One teaspoon treats ten gallons.

Sources of water testing Kit:

Water analysis kit: E-Merck, India, Qualigens, Aquarium & Aquarium Supplies in Kolkata

A G Aquariums

56/6, Kantapukur, 3rd Bye Lane, Kadamtala, Howrah-711101 (91-33)-26774736

Chakraborty Aquarium

188/1, New Alipore, Block-J, Kolkata 09830119329

Aquarist Centre

2f Marquis Street, Park Street Kolkata

033 22522700

09830089707 – Mobile

Das Aquarium

17, 17 S N Roy Road, Sahapur, Calcutta - 700038

Phone : 24574505

Wonder Shells come two ways; regular and medicated:

The Regular Wonder Shells are great for ph, KH, water clarification, chlorine removal and more. It helps keep aquarium clear. Maintains stable pH. Adds necessary minerals (electrolytes). Removes chlorine. Great for Goldfish, livebearers, cichlids, and more. It contains Calcium carbonate; sodium thiosulfate; major, minor, and trace elements including magnesium sulfate. Magnesium and calcium been proven to help fish (and humans) during stress and to help prevent disease due to acid buildup in the body.

Dolphin Aquarium Centre

530a, 530a Jodhpur Park, Jodhpur Park, Calcutta - 700068

Phone : 9831137503

Ghosh’s Aquarium

178, R B Avenue, Sarat Bose Road, Calcutta - 700029

Phone : 24631018

T S Traders

17, S N Roy Road, Sahapur, Calcutta - 700038

Phone : 24465777

Aqua Tech Enterprises, Kolkata, Kidderpore ...

Bengal Aquaculture

54 Ichhapur Road, Kadamtala, Howrah Ph. – 9433627089, 9831592050

Others:

HOLLYWOOD AQUATIC PRODUCT

AQUARIUM & AQUARIUM ACCESSORIES Aquarium & Acquaculture, NO. 1, BHARATHI NAGAR, BALAJI NAGAR MAIN ROAD, KOLATHOOR, CHENNAI-600099, TAMILNADU. T.N. KUMAR Phone : 044-25379659 Fax : 044-25500800

SOUTHERN INDIA AQUARISTS

AQUA CULTURE ITEMS, FISH MEDICATIONS, PRAWN FEEDS, ETC. Aquarium & Acquaculture. 8, GIRI ROAD, T. NAGAR, CHENNAI-600017, CHENNAI. MRS. KUMAR (DIRECTOR - MARKETING) Phone : 044-28255825 /28252752 Fax : 044-28259524 siac@eth.net , http://www.archanaexports.com

Living World

Shop No. 18 Crawford Market Fort Mumbai-400001, Maharashtra, Phone : 022-23422496

Fish-N-Fun

Shinde Wadi Dr Ambedkar Road Dadar Mumbai-400014, Maharashtra, Phone : 022-24147893

Water Pets

Deals in aquariums, fish & accessories, 46/7 Urban Estate, Gurgaon-0, Phone : 0124-2300312.

Aqua Scape, Mumbai, Napean Sea Road. Aqua Scenes Aquarium Centre, Udupi, Badagubettu.

List of Ornamental Fish Exporters

M/s Angelo

8 A, Radhanath Mullick lane, Calcutta,700 012

Tel: # +91 33 2415478

Fax : +91 33 2415478 /4748172 Contact Person : Mr.Sumit Dutta E-mail : links@satyam.net.in M/s Aqua Decor

77, Netaji Subash Road, first Floor, Suite No 111

Calcutta- 700 001

Phone : +91 33 243 1191/2105635 Fax : +91 33 210 5359 /440 6389 E-mail : aquadeco@giascl01.vsnl.net.in

Contact person : Mr. K.L.Tekriwal

M/s Aquatic World

Rahat Basar Manzil, 1 st Floor 1D Fort Road, Mahim

Mumbai-400 016 Phone : +91 22 4457749 Fax : +91 22 4457749

Contact Person : Mr. Mehamood Syed

M/s Aquatic Exortica

5/B, Viswagith Bldg

Vakola Bridge, Santacruz (E) Mumbai- 400 055

Phone : +91 22 6140340 Fax : +91 22 6174942

Contact Person : Mr. Kalpesh U KIni

M/s Asian Exports

2, Ganesh Chandra Avenue 7 th floor, Calcutta-700 013 Phone : +91 33 277852 Fax : +91 33 2250269

E-mail- deepak@gias101.vsnl.net.in

Contact Person : Mr.Deepak

M/s Floating Beauty

73, Nandakumar Sadan

Road No 5, Sreekrishnan Nagar, Borivali (E), Mumbai - 400 066,

Tel. # 0091 22 8952314, Fax: 0091 22 8952314.

M/s Howrah fancy Fish

91/1, Netaji Subash Road Howrah- 711 101

Phone :033 6501341

M/s Sachetan

L/45, Sitaram Building, Palton Road, Mumbai - 400 001

Tel. # 0091 22 3448795 Fax: 0091 22 5221617

Contact Person : Mr. S R Sane M/s Southern India Aquarists

No. 8, Giri Road, T Nagar, Chennai - 600 017

Tel. # 0091 44 8255825 Fax: 0091 44 8259524 e-mail: archana@xlweb.com

Contact Person : Mr. Kumar.

M/s Trident International

10, Kennaway House 63-A, Proctor Road Mumbai - 400 004 Tel. # 0091 22 3872398 Fax: 0091 22 3872398

Contact Person : Mr. Vispi Mitri

M/s Travancore Aquapets

IV, 342 A, Kollayil House Kumbalam, Cochin - 682 506 Tel. # 0091 484 313227 Fax: 0091 484 312485

e-mail: krpushpangadhan@hotmail.com

Contact Person : Mr. K R Pushpangadhan

M/s Amalgam Aquaculture

Bristow Road, Willington Island Cochin - 682 003

Tel: # 0091 484 668680 Fax: 0091 484 668130/668133 Contact Person : Mr. A J Tharakan.

M/s Umang Exports

77, Netaji Subash Road 1st Floor, Suit No III Calcutta-700 001 Phone -+91 33 2431191 fax - +91 33 2105359

Contact person :- Mr. K.L. Tekriwal

M/s Sur Aquapet Enterprises

21 A, Badridas Temple road, calcutta- 700 004

Phone-+91 33 3505768 Fax - +91 33 2486871

contact person: Mr. Pradip Kr.paul

M/s Kundu's Fancy Fish Supplies

Sanpur Sibtala,Dassnagar, Howrah-711105

Phone -+91 3 692 848

Contact Person-Mr.prasantha Kumar Kundu

M/s Howrah aquarium

100, Netaji Subash road, Howrah- 711 101 Phone- +91 650 7106

Contact Person- Mr. Naba Sarkar

M/s A M Enterprises Flat No 11, 1st Floor 55, Gariahat Road Calcutta-700 019 Phone-91 33 4749652 Fax-+91 33 4748490 M/s Pescina Indica 21/1, jodpur Colony, P O Lake gardens Calcutta Phone +91 33 4634370

M/s Chandrlok International traders

17/6 Raja Rajkission street, Calcutta-700006

Phone-+91 33 555 8598 +91 33 339432

Contact person- Mr. Atish Chandra Sinha

M/s Karson(India)

5,Dharmatala Street, Calcutta-700 013 Phone-+91 33 284579 Fax-+91 33 281081

Contact Person: Mr.Narinder Pal singh

M/s S.S. Pet Fish farm

21 a, Badridas Temple Street, Calcutta -700 006

Phone-91 33 2356541

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MANAGEMENT OF WATER QUALITY IN AQUARIUM

Introduction:

Fish obtain their basic necessities from the water in which they live. The most characteristic feature of any aquarium system is therefore the quality of the water it contains. This water must be obtained from some source, pre-treated to make it suitable for the fish, delivered to the fish in sufficient quantities and maintained in good condition. Finally, it must be disposed of.

The water supplied to an aquarium is not pure, but contains dissolved and particulate materials, some are necessary for the well-being of the fish and others are harmful.

Contamination may occur not only at source or form the animals, but often takes place within the aquarium form the materials used in its construction. The volume of water supplied

to an aquarium may at first sight, seem to restrict the number of fish that can be maintained within it. However, it is rarely the quantity of water per unit which limits the carrying capacity. The capacity is usually set by the consumption of dissolved oxygen and the accumulation of toxic metabolic products.

Nitrogenous waste products:

Perhaps the most pronounced and damaging changes to water quality originate with the aquarium inhabitants themselves. In particular, water quality is impaired by the end products of nitrogen metabolism. These include ammonia (either as the gas NH3 or

ammonium ion, NH4), urea, uric acid and other nitrogenous substances including proteins and

amino acids. Ammonia, especially, is one of the most harmful substances. Higher percent of un-ionized NH3 prevails at higher pH and higher temperature. In ammonia poisoning, Gill

becomes red, fish become darker in colour and grasping at the surface layer. Acute toxicity levels = 0.4 ppm NH3. Chronic toxicity levels = 0.05 ppm. This is common in new aquarium

when immediately stoked to full capacity. Ammonia can damage the gills at a level as small as 0.25 mg/lt. For immediate removal of ammonia, use ammonia detoxifier such as Kordon's Amquel. However, it is best left alone until the bacterial load is sufficient. Note that the bacterial phases will not take place unless the tank is initially stocked with feeder fish which can be removed after treatment. Test the water until the ammonia drops to nearly zero. At this time, we should notice an increase in the nitrite level. When the nitrites are gone, it will be safe to add fish.

The conversion of the more toxic nitrogenous compounds to less toxic compounds is achieved through organisms residing in water treatment units such as filters. In some aquaria, algae are also used in nitrogen recycling. The process of combating the effects of nitrogenous waste products is facilitated by low stock density, a high water turn over, aeration or oxygenation of the water, frequent cleaning, removal of faeces and waste food and by the provision of special water treatment facilities.

Dissolved oxygen:

The majority of aquatic organisms need oxygen and must obtain it from the surrounding water. The oxygenation or aeration of the water is therefore, of fundamental

importance in any aquarium, especially as the oxygen supply is one of the factors which may ultimately limit the capacity of a particular volume of water for carrying fish.

The oxygen dissolved in water comes from two main sources: the atmosphere and green plants. The actual content is a function of temperature, salinity and atmospheric pressure. Low temperature, low salinity and higher atmospheric pressure favours more gas content (thereby more oxygen) in the solution (water medium).

Aeration: Continuous aeration is very good husbandry since it mixes the water, supplies the oxygen for the fish, removes carbon dioxide and maintains a constant temperature throughout the tank. Many cheap air pumps are available in the hobby trade, though they are often noisy, are of limited power and many frequently fail. If only one or two tanks are required, such vibratory diaphragm pumps are acceptable, but a spare pump and several replacement diaphragms should be stocked. The pump should be mounted above the tank level or the air-line fitted with non-return valve to prevent back-siphoning when the pump is stopped or fails. A loop in the air-line 8 cm (3 inch) vertically above the tank’s water level will also prevent back-siphoning by absorbing the oscillations when the airflows stops. The air tubes from the pump are connected to air stones for providing minute air bubbles that diffuses the oxygen in water. Besides that it is also connected to various types of toys and also for airlift pumping under for under gravel filtration. For diffusion of more oxygen in water a micro pore air stone gets priority during selection of air stones.

Water Temperature:

Temperature is perhaps the most potent of all the environmental factors controlling and governing the metabolism of animals. Water has a high thermal capacity compared to air; that is, it can absorb a large amount of heat energy for a small rise in temperature. It, therefore, provides a thermally stable environment.

In aquarium, fish are largely denied the use of any behavioural regulation, and the aquarium design and management must compensate for this loss. Sudden change of temperature in the aquarium should be avoided. Such as thermal shocks are most likely to occur when fish are transferred from tank to tank or when they first arrive in the aquarium complex. A simple rule is to float transfer containers plus fish in their new tanks until the temperature has equilibrated or alternatively to slowly mix the water in the container with that in the tank over half an hour or more. Increases in temperatures have the most distressing

effect since respiration rate and excitability increase while the oxygen-carrying capacity of the water decreases. Such temperature increase in established tanks may result from refrigeration breakdown or thermostat malfunction. The damage cause by faulty thermostat in a heated system can be minimized by employing the minimum wattage heaters required for the temperature control or by including a high temperature cutout in the circuit. This could simply be a second thermostat in series with the first, but set to a slightly higher temperature so that it is on all the time during normal operations. Such a thermostat should, however, be serviced regularly to ensure it does not stick on.

During winter months necessary heating arrangements may be made for tropical aquarium fish. A water heater of 5-6 watts capacity is required per gallon of water. Heating equipment of the aquarium is basically an electric heating coil complete with thermostat to control it both contained in glass tube. This submerged in the aquarium, connected to the electricity supply and the built-in neon indicator. A thermometer is always kept in side the aquarium to monitor the temperature. It is placed at the front where it can be easily seen. It is best arranged heater and thermostat at opposite corners of the tank to get correct temperature readings of the aquarium water.

Sound and Vibration:

It is often forgotten that many fishes are acutely sensitive to sound and other mechanical disturbances of the water. Though the hearing of most species is restricted to low frequencies (below 3 kHz for nearly all fish, and below 1 kHz for most), at these low frequency and amplitude many species produce sounds especially during courtship.

The aquarium is often a very noisy place, with underwater noise levels in aquarium tanks often very much higher than those in the sea or in freshwater. Much of the noise comes from the machinery; pumps and compressors associated with the aquarium, and characteristically contain strong single frequencies in its spectrum. Human footfalls, doors opening and closing etc. can also be troublesome, and their strongly impulsive nature may evoke startling response from the aquarium inhabitants. Vibration is transmitted to the water mainly through the floor and tank supports but also through the water pipes. Therefore, machinery; pumps and compressors, which are producing unnatural sound, must be replaced at the earliest.

Routine cleaning:

Routine partial changes of the water are most important. The changes are necessary to dilute the build-up of soluble materials (due to accumulation of fecal and unfed materials). The ideal is to replace 20% of the tank volume weekly. Evaporation losses should be replaced by suitable water (artificially prepared or natural). The cleaning can be done by hand; the hands should be washed with shop, after the job and not before because of the danger of introducing soap into the water. Use scraper for algae on glasses. The toys, air stones and other equipments, which have the algae and other sediment attachment, should also be cleaned. Plants should be trimmed and decaying leaves should be removed regularly at the time of water exchange.

Some important aspects of water quality:

Aquarium should be filled with clear portable water. The quality requirement of water in the aquarium depends on the types of the fishes being kept there. The tap water is probably the safest source of aquarium water for majority of tropical fish and plants (see below the requirement for breeding). But it contains chlorine, which is toxic to fish even at low concentration. To remove the chlorine naturally, it is better to allow maturing the water for few days or aerating overnight before its addition. During emergency conditions dechlorination can be done with the commercially available chemical (sodium thiosulphate) purchased from the pet shop.

The degrees of hardness have several biological effects upon aquatic life. Bicarbonates tend to prevent a solution from changing in acidity. Soft water, lacking this protection, may become particularly acidic when much carbon dioxide is present; such a change creates stress for organisms. For soft water species excessive hardness causes an organism problem in absorbing substances through its delicate membranes. This is most true of the sensitive naked cells of eggs and milt, so that soft water has been found to play a vital role in the successful reproduction of many species of freshwater fishes. Thus, at least for the purposes such as fish breeding, a soft solution is desirable. Water hardness typically follows the following guideline:

Hardness scale Water hardness level (as CaCO3) Hardness level 0-4 dH 4-8dH 8-12 dH 12-18 dH 18-30 dH 0-70 ppm 70-140 ppm 140-210 ppm 210-320 ppm 320-530 ppm 60-100 ppm Very soft Soft Medium hard Fairly hard Hard Desirable hardness

To maintain soft water, all sources of calcium carbonate such as calcareous rocks, gravels, coral, broken shell and algae must be kept out of the aquarium system whilst using only soft water initially and during exchange. Conversely, presence of such sources will preserve the water hardness. Some of the important water quality parameters and their optimum ranges for aquarium fish are presented in the table below:

Temperature pH CO2 Alkalinity Hardness Dissolved oxygen Free ammonia Ionised ammonia 24-280C 7.0-8.5 < 5 ppm 75-120 ppm as Ca CO3 60-100 ppm as Ca CO3 6.0-8.0 ppm <0.05 ppm <0.1-0.4 ppm Sources of Informations: 1. http://www.diveintofish.com 2. http://hbhnet.com/PetCare 3. http://edis.ifas.ufl.edu 4. http://ezinearticles.com 5. http://www.mypets.net.au 6. http://www.peteducation.com 7. http://www.aquaticcritter.com/Freshwater/aquariummaintenance 8. http://hbhnet.com/PetCare 9 http://www.goldfishvet.com 10. https://www.blogger.com

11. Russ Case (Ed). Freshwater and Marine Aquarium, BowTie Magazines, 150p. 12. Glenn S. Axelrod (Ed.) Tropical Fish Hobbyist, TFH Publications Inc., 200p.