# Sticky  Aquarium Chemistry



## CLUSTER ONE

Article is still in the works. Post here or pm me with any corrections, additions, changes, spelling/grammatical errors... that you would like to do.

*Aquarium Chemistry- What it all means?*

*Ammonia/Ammonium (NH3/NH4+)* - Ammonia is the natural product of the decomposition of organic substances. Proteins in living things such as plants, animals and microorganisms all contain amino groups. An amino group is NH2. As you can see an amino acid (found in proteins) contains all the required atoms in order to form ammonia or ammonium molecules. In an aquarium, ammonia exists in two different forms that are both extreamly toxic to aquarium inhabitants. These two forums are ammonia (NH3) and an ionized ammonia called ammonium (NH4+). In general as temperature and pH increase, ammonia (NH3) will be present as opposed to ammonium (NH4+). Though both are toxic to aquarium inhabitants, ammonia (NH3) is much more toxic then ammonium (NH4+). This means that if a certain amount of ammonia is present it may be lethal as the aquariums temperature and pH increase but be merely stressful to fish in a cold water aquarium with an acidic pH.

Ideal aquarium reading: 0ppm









*Some fish are more hardy then others. An ammonia concentration may be lethal to one fish may not necessarily be lethal to another. The safest level of ammonia is 0ppm regardless of pH or temperature. The main thing to understand is that ammonia is more toxic as pH and temperature increase.

*Nitrite (NO2-)* - Through "The Nitrogen Cycle," ammonia is converted into less toxic nitrite (NO2-). A certain bacteria accomplishes this by reacting ammonia with water to form nitrite. Excess levels nitrite (NO2-) can lead to "Nitrite Poisoning/Brown Blood Disease." Some symptoms of Nitrite Poisoning/Brown Blood Disease include fish: gasping for air at the water's surface, attempting to stay in moving oxygenated water rapid breathing, discoloured gills and fatigue. Effected fish will have reduced ability to carry oxygen in their blood and are therefore on the verge of suffocating if they cannot receive enough oxygen.

Ideal aquarium reading: 0ppm. Levels as low as 0.5ppm can cause stress to fish. Higher levels can be potentially lethal.

*Nitrate (NO3-)* - A certain Nitrifying bacteria accomplishes this by reacting nitrite (NO2-) with water to form nitrate (NO3-). Nitrates (NO3-) can be removed from an aquarium through water changes and through consumption by aquarium vegetation. Though nitrate (NO3-) is not as toxic as ammonia or nitrite, it can still be detrimental and even lethal at higher concentrations. Since plants will consume nitrate (NO3-), excess nitrate (NO3-) can lead to unwanted algae growth.

Ideal aquarium reading: <40ppm

*Potential Hydrogen/ Power of Hydrogen (pH)* - Potential Hydrogen as it sounds is a scale that measures the relative hydrogen (relative to hydroxide) concentration of (in our case) the aquarium water. In general the pH scale is from 1-14 with 7 being neutral. Below 7 is considered to be acidic while above 7 is called basic. Many people wrongly confuse "pure water having a pH of 7" for "having a pH of 7 is ideal". This confusion leads to many people using buffers to attempt to adjust their pH. A buffer is a conjugate acid-base pair that will keep the pH relatively stable even when an acid or base is added to the system. While the use of a buffer is ideal for pH values that are way off from ideal or for fish that accept only a small range of pH values, it is not necessary for the vast majority of aquarium applications. Most fish thrive in a wide range of pH values. If one chooses to use a buffer they must ensure that it is used consistantly in order to insure a relatively constant pH.

Basic pH Calculations
*Not nessisary to know though it shows well how the pH relates to the waters hydrogen ion concentration.

H2O <--> H+ + OH- (Water <-->Hydrogen ions + hydroxide ions)

pH = log10[H+]
[H+] = 10^pH

One of the most important things that I believe too few of people know is that the pH scale is logarithmic. This means that an increase of just one value on the pH scale is in reality a 10X increase or decrease in acidity/alkalinity of a solution. Many people view a change in pH as not overly significant though they fail to realize a change in 2 pH values (ex. from 6 to 8) is a 100x increase or decrease in acidity/alkalinity and a change in 3 pH values is a 1000x increase or decrease in acidity/alkalinity. When the pH scale is looked at in this manner a fluctuating pH seems much more significant.

Ideal aquarium reading- For piranhas, a pH in the slightly acidic range (approximately 6.6) is ideal. Other types of fish may tolerate a pH between 5-8.5. Unless your pH is significantly off from the ideal value or you are dealing with a sensitive species of fish. Captive bred fish that have been captive for a few generations are often hardier then wild caught fish It is often best to let your fish adapt to your pH rather than try to constantly adjust it. Any fish should be slowly acclimated to any significany change in water chemistry.

*General Hardness/ Total Hardness (GH/TH)* - General Hardness is a measure of all of the dissolved mineral salts in the water. As general hardness increases, there are more dissolved salts present in the water. General Hardness primarily measures the presence of calcium (CaC03) and magnesium in the water. The concentration of dissolved salt affects the osmotic regulation systems present in fish (controls a fish's internal salt concentration). Osmotic regulation serves to replenish essential ions in the blood. Hard water species will excrete calcium while soft water species require an intake of calcium in order to form their skeletal structure.

GH is commonly measured in parts per million (ppm) of CaCO3 or degree hardness (dH).








*A chart that outlines the basics on what is considered to be soft, medium and hard water

dH to ppm = dH x 17.9
ppm to dH =ppm/17.9

Ideal aquarium reading: A soft-medium water hardness is ideal for piranhas though not mandatory.

*Carbonate Hardness (KH)* - On a basic level, KH is a buffer that helps to stabilize the aquarium water at a certain pH with the use of calcium carbonate. Once again, a buffer is a conjugate acid-base pair that will keep the pH relatively stable even when an acid or base is added to the system. Carbonate hardness is the measue of bicarbonate (HCO3) and carbonate (CO3-) ions in the water.

Alkalinity- A term that refers to the buffering capacity of a carbonate-bicarbonate system (below).

CO2 + H2O --> H2CO3 --> HCO- + H+ --> CO32- (solid) + 2H+

According to Le Chatelier's principle, when a chemical system at equilibrium is disturbed by change in property (ex. an acid or base is added/removed) the system will react to oppose the change (ie. re-establish equilibrium).

The higher the KH value and the more buffering ability the less likely you will have a fluctuating pH. Generally a high KH is associated with a high pH. Distilled or RO water often have very little to no buffering ability therefore do not aid in keeping the aquariums pH stable and because of this if distilled or RO water is used it should either be mixed with tap water or have buffering chemicals and essential trace elements added.

Once again:
dH to ppm = dH x 17.9
ppm to dH =ppm/17.9

Ideal aquarium reading: 40-80ppm is ideal for fish like piranhas that prefer slightly acidic conditions. I would recommend testing for KH periodically to see how much you should worry about a fluctuating pH.








*An interesting graph showing the cause and effect associated with various intentional changes to an aquarium

*All pictures were found through the internet and are not products of my own work.


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