The Importance Of Freshwater Aquarium PH
PH measures the degree of acidity or alkalinity present in the water of your aquarium. The scale ranges from 0 to 14 with 0 being the most acidic, 7 being neutral, and 14 being the most alkaline. Most fish thrive in a pH range of 6.4 to 7.8 but there are exceptions.
The ph scale is logarithmic which means in simple terms that a very small change in value is a very large change in acidity or alkalinity.
It is changes in pH value that affect your fish much more than the actual pH value. While a fish may prefer a pH of 7.2 it will most likely be perfectly happy with a pH of 6.7. However the same fish will become extremely stressed if you have a pH swing of 0.3 over the course of a day.
Most aquarists deal with the pH issue by keeping it as constant as possible and getting their fish used to living in that environment. Constant measns that the pH should nt range by any more than 0.2 over 24 hours.
In some cases breeding only takes place at a particular pH value. If you plan to breed a certain species, research the range of pH it finds acceptable to breed in. Some varieties are easily pleased while others have a very small range. This is probably the only good reason why you might want to aim for a particular pH value.
Factors Affecting pH
- Biological filtration As everyone knows, good filtration is one of the essentials of a well stocked aquarium. Biological filters reduce pH because they release carbon dioxide into the water.
- Carbonate Hardness Carbonate hardness or kH is a measurement of the carbonate hardness of your water. The harder your water i.e. the higher its kH then the better the water is at neutralising acids without a major change in pH. It is called your water’s ‘buffering capacity’, generally speaking, kH should be above 4.5.
Adjusting pH
Changing the water regularly (which you should be doing anyway) is a good way of keeping the pH at an appropriate level.
Acclimatising your fish to the pH provided is the best way to deal with pH but you can change it as shown below.
How to Lower the pH
- Filtering water over peat
- Add bogwood to the tank
- Inject carbon dioxide CO2
- Use a commercial acid buffer
- Water changes with softened water or RO/DI (Reverse Osmosis/De-Ionized) water
How to Raise the pH
Raising the pH makes the ammonia in the water more toxic to your fish so this should be done with great care.
- Aerate the water, to drive off excess carbon dioxide (CO2)
- Filter over coral or limestone
- Add rocks containing limestone to the tank or use a coral sand substrate
- Use a commercial alkaline buffer
Conclusion
It is much more important to have a stable pH than to have a specific value for your pH. To obtain a reasonably stable pH the carbonate hardness should be about 5-6 dH so that the water has a reasonable ‘buffering capacity’.
Even small swings of more than 0.2 pH in a day can cause your fish to die. You should therefore not attempt to tamper with the pH unless you have a very good reason for doing so.
For more information on freshwater aquarium pH go to my website www.freshwateraquariumsecretsonline.com
