| PH measures the degree of acidity or alkalinity | | | | your water's 'buffering capacity' a good kH is above |
| present in the water of your aquarium. On the pH | | | | 4.5. |
| scale 0 is the most acidic, 7 is neutral and 14 is the | | | | Adjusting pH |
| most alkaline. Most fish happily tolerate anything | | | | Frequent water changes (which you should be doing |
| between 6.4 and 7.8 but there are some | | | | anyway) are the best way to keep the pH up to an |
| exceptions.pH is a logarithmic scale, in simple terms | | | | appropriate level. |
| this means that a small change in value indicates a | | | | As stated above you should acclimatise your fish to |
| very large change in acidity or alkalinity. | | | | live in the ph that you provide but if it is necessary |
| It is much more important that you maintain a | | | | to change the ph for any reason then here's how. |
| consistent pH. While a fish may prefer a pH of 7.2 it | | | | How to Lower the pH |
| will most likely be perfectly happy with a pH of 6.7. | | | | - Filtering water over peat |
| However that same fish will be really stressed if it | | | | - Add bogwood to the tank |
| has to endure a pH swing of 0.3 in a day. | | | | - Inject carbon dioxide CO2 |
| Most aquarists deal with the pH issue by keeping it as | | | | - Use a commercial acid buffer |
| constant as possible and getting their fish used to | | | | - Water changes with softened water or RO/DI |
| living in that environment. Constant means that the | | | | (Reverse Osmosis/De-Ionized) water |
| pH should not change by any more than 0.2 over 24 | | | | How to Raise the pH |
| hours. | | | | Raising the pH makes the ammonia in the water |
| In some cases breeding only takes place at a | | | | more toxic to your fish so this should be done with |
| particular pH value. If you are hoping to breed a | | | | great care. |
| certain variety then you will need to research their | | | | - Aerate the water, to drive off excess carbon |
| preferred pH range. Some species have a very tight | | | | dioxide (CO2) |
| range while others are more forgiving. This is | | | | - Filter over coral or limestone |
| probably the only good reason why you might want | | | | - Add rocks containing limestone to the tank or use a |
| to aim for a particular pH value. | | | | coral sand substrate |
| Factors Affecting pH | | | | - Use a commercial alkaline buffer |
| - Biological filtration As you already know, filtration is | | | | Conclusion |
| essential in a well stocked aquarium. Biological filters | | | | The particular pH value is not so important, what is |
| reduce pH because they release carbon dioxide into | | | | important is to have a reasonably constant pH value. |
| the water. | | | | To achieve this the kH should be around 5-6 dH in |
| - Carbonate Hardness Carbonate hardness or kH is a | | | | order for the water to have enough buffering |
| measurement of the carbonate hardness of your | | | | capacity. Swings of just 0.3 pH in a day can be |
| water. A high kH (i.e. the harder your water) the | | | | deadly to your fish. Unless you have good reason it is |
| better is the water able to neutralise added acids | | | | best to leave the pH alone unless you have a specific |
| without significantly changing the pH. This is known as | | | | reason for changing it. |