Welcome to www.fishkeepinguk.co.uk

Water Chemistry
Water Hardness (GH & KH) Water hardness is related to the disolved mineral content of the water and is calculated by the sum of the temporary or bicarbonate hardness (KH) (the hardness that can be reduced by boiling) & general hardness (GH) which cannot be boiled off. If temporary hardness is low, this reduces the buffering capacity of the water, therefore the PH & water quality can fluctuate rapidly. Fish from certain geographical regions may have specific requirements for permanent hardness conditions. Very Soft 0-50 mg/l (ppm) Moderatly Soft 50-100mg/l Slightly Hard 100-150mg/l Moderatly Hard 150-200mg/l Hard 200-300mg/l Very Hard 300+mg/l Water Hardness can be increased by adding limestone decor or commerical salts to the aquarium or if using a canister filter using coral sand. Reducing water hardness is possible by using reverse osmosis (RO), distilled, deionised (DI) or rainwater to dilute tapwater, if your tapwater has a GH of 10 and you use half tapwater and half pure water, the GH will be 5. The content below reproduced with kind permission of Sean @ www.thetropicaltank.co.uk Acidity/Alkalinity (PH) Acidity & alkalinity are measured on a scale of 1 to 14 with 1 being acid and 14 being alkaline. 7 is neutral conditions and most freshwater fish prefer PH values between 6 and 7.5. Commerical solutions are available to adjust the PH either up or down. Ammonia (NH4+ & NH3) The ammonia level should always be zero (that is, undetectable by conventional kits) in a mature aquarium. Filter failures, or the addition of a large number of additional fish, may cause a temporary rise in ammonia levels before the bacterial population increases to cope with the demand. Fish waste, uneaten food and decaying plant matter will all contribute to the level of ammonia in the tank. Ammonia poisoning is more common at alkaline pH. Ammonia can cause damage at levels of only 0.1 ppm. There may be haemorrhaging and destruction of mucus membranes, the gills are particularly likely to be damaged. As with nitrite poisoning, fish may apppear to gasp for air at the surface, and show rapid gill movement. Higher levels, of several ppm, can be fatal. A partial water change, removal of uneaten food or decaying plants, and checking the function of the filter can help reduce Ammonia. In a mature aquarium, ammonia is oxidised by bacteria to form nitrites Nitrite (NO2) The nitrite level should always be zero in a mature tank. As with ammonia, a temporary rise in nitrite levels may be seen after filter failures or the addition of a large amount of fish. A nitrite level of only 0.1 ppm could prove harmful if exposure is prolonged. Symptoms of nitrite poisoning include gasping and rapid gill movements, which could be mistaken for a shortage of oxygen. In extreme cases, fish can actually die of suffocation because nitrite binds to the oxygen-carrying component (haemoglobin) in the blood. A partial water change, and checking the function of the filter can help reduce nitrate. In a mature aquarium, nitrite is oxidised by bacteria to form nitrate Nitrate (NO3) In the past, nitrate was considered essentially harmless to fish; certainly it is far less toxic than ammonia or nitrite. It has been shown that levels of up to 1000 ppm may be required to cause death, but the effects of lower levels on long term health are not well understood. The sensitivity of different species to nitrate levels varies, and there may be long term effects on general health, growth and breeding ability. Generally, many aquarists seem to agree that keeping nitrates below 50 ppm is necessary to prevent any long-term effects on fish health, but below 25 ppm is more desirable. Remember that many fish may come from a natural environment where there is little or no detectable nitrate. Fish which have been aquarium bred for generations are more likely to tolerate nitrates. Chorine Chlorine (and sometimes chloramine) are added to tap water to make it safe for humans to drink. Unfortunately, this makes it less suitable for use in the aquarium because both chlorine and chloramine are harmful to aquatic life. Lower levels could cause stress and irritate the gills of fish, higher levels (around 0.2ppm) could be fatal. Chlorine can be removed fairly easily in a number of ways. One method is to simply allow the water to stand for about 24 hours (preferably with aeration) until it evaporates. There are also several brands of commercial de-chlorinators available and some of these water conditioners contain extra ingredients to bind toxic heavy metals or add a protective slime layer to the fish. Chloramine is a more persistant chemical, and some water authorities use it because of its greater stability. If you know or suspect that the water authority in your area uses chloramine, check that your dechlorinator product removes it. Chloramine is a compound of chlorine and ammonia, which is more stable than chlorine alone. Traditional dechlorinators, based on sodium thiosulphate, will neutralise the chlorine part, but this releases the ammonia. With a large percentage water change, this could be dangerous or stressful for the fish, as the bio-filtration will need time to convert the ammonia. The solution is a product which deals with the chlorine part and also converts the ammonia into a non-toxic form. Fishkeepinguk accepts no liability for any incorrect information, advice, or content included on the website

Water Hardness (GH & KH)

Water hardness is related to the disolved mineral content of the water and is calculated by the sum of the temporary or bicarbonate hardness (KH) (the hardness that can be reduced by boiling) & general hardness (GH) which cannot be boiled off. If temporary hardness is low, this reduces the buffering capacity of the water, therefore the PH & water quality can fluctuate rapidly. Fish from certain geographical regions may have specific requirements for permanent hardness conditions.

Very Soft 0-50 mg/l (ppm)
Moderatly Soft 50-100mg/l
Slightly Hard 100-150mg/l
Moderatly Hard 150-200mg/l
Hard 200-300mg/l
Very Hard 300+mg/l

Water Hardness can be increased by adding limestone decor or commerical salts to the aquarium or if using a canister filter using coral sand.

Reducing water hardness is possible by using reverse osmosis (RO), distilled, deionised (DI) or rainwater to dilute tapwater, if your tapwater has a GH of 10 and you use half tapwater and half pure water, the GH will be 5.

The content below reproduced with kind permission of Sean @ www.thetropicaltank.co.uk

Acidity/Alkalinity (PH)

Acidity & alkalinity are measured on a scale of 1 to 14 with 1 being acid and 14 being alkaline. 7 is neutral conditions and most freshwater fish prefer PH values between 6 and 7.5. Commerical solutions are available to adjust the PH either up or down.

Ammonia (NH4+ & NH3)

The ammonia level should always be zero (that is, undetectable by conventional kits) in a mature aquarium. Filter failures, or the addition of a large number of additional fish, may cause a temporary rise in ammonia levels before the bacterial population increases to cope with the demand. Fish waste, uneaten food and decaying plant matter will all contribute to the level of ammonia in the tank.

Ammonia poisoning is more common at alkaline pH. Ammonia can cause damage at levels of only 0.1 ppm. There may be haemorrhaging and destruction of mucus membranes, the gills are particularly likely to be damaged. As with nitrite poisoning, fish may apppear to gasp for air at the surface, and show rapid gill movement. Higher levels, of several ppm, can be fatal.

A partial water change, removal of uneaten food or decaying plants, and checking the function of the filter can help reduce Ammonia.

In a mature aquarium, ammonia is oxidised by bacteria to form nitrites

Nitrite (NO2)

The nitrite level should always be zero in a mature tank. As with ammonia, a temporary rise in nitrite levels may be seen after filter failures or the addition of a large amount of fish. A nitrite level of only 0.1 ppm could prove harmful if exposure is prolonged. Symptoms of nitrite poisoning include gasping and rapid gill movements, which could be mistaken for a shortage of oxygen. In extreme cases, fish can actually die of suffocation because nitrite binds to the oxygen-carrying component (haemoglobin) in the blood.

A partial water change, and checking the function of the filter can help reduce nitrate.

In a mature aquarium, nitrite is oxidised by bacteria to form nitrate

Nitrate (NO3)

In the past, nitrate was considered essentially harmless to fish; certainly it is far less toxic than ammonia or nitrite. It has been shown that levels of up to 1000 ppm may be required to cause death, but the effects of lower levels on long term health are not well understood. The sensitivity of different species to nitrate levels varies, and there may be long term effects on general health, growth and breeding ability.

Generally, many aquarists seem to agree that keeping nitrates below 50 ppm is necessary to prevent any long-term effects on fish health, but below 25 ppm is more desirable. Remember that many fish may come from a natural environment where there is little or no detectable nitrate. Fish which have been aquarium bred for generations are more likely to tolerate nitrates.

Chorine

Chlorine (and sometimes chloramine) are added to tap water to make it safe for humans to drink. Unfortunately, this makes it less suitable for use in the aquarium because both chlorine and chloramine are harmful to aquatic life. Lower levels could cause stress and irritate the gills of fish, higher levels (around 0.2ppm) could be fatal.

Chlorine can be removed fairly easily in a number of ways. One method is to simply allow the water to stand for about 24 hours (preferably with aeration) until it evaporates. There are also several brands of commercial de-chlorinators available and some of these water conditioners contain extra ingredients to bind toxic heavy metals or add a protective slime layer to the fish.

Chloramine is a more persistant chemical, and some water authorities use it because of its greater stability. If you know or suspect that the water authority in your area uses chloramine, check that your dechlorinator product removes it. Chloramine is a compound of chlorine and ammonia, which is more stable than chlorine alone. Traditional dechlorinators, based on sodium thiosulphate, will neutralise the chlorine part, but this releases the ammonia. With a large percentage water change, this could be dangerous or stressful for the fish, as the bio-filtration will need time to convert the ammonia. The solution is a product which deals with the chlorine part and also converts the ammonia into a non-toxic form.

Fishkeepinguk accepts no liability for any incorrect information, advice, or content included on the website