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Water quality management in freshwater Aquariums for culture and breeding of aquarium fish

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).

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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

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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

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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.

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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.

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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.

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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

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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.

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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.

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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. Vikas Fish Aquarium and Dogs Kennel (Aquarium and Aquarium Supplies – Delhi.

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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. Subhashis Sur

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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

Want to read more on this topic? Just go ahead....

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

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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

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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

15

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.

16

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:

17

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.