subject: Freshwater Aquarium PH - Is This Something To Worry About? [print this page] Freshwater Aquarium PH - Is This Something To Worry About?
PH is a measure of the acidity or alkalinity of the water. Its values range from 0 to 14. 0 being the most acidic, 7 being neutral and 14 being the most alkaline. It is a logarithmic scale which means that a pH of 6 is ten time more acidic than a pH of 7.
Many aquarists worry about the level of the pH in their aquarium. The truth of the matter is that most fish will acclimatise to a range of pH anywhere from 6 to 8. Bear in mind that a pH of 6 is 100 times more acidic than a pH of 8 so this is a very wide tolerance.
Factors Affecting pH
It is important to understand what factors affect the pH of your water. The most important factor is the water's buffering capacity. This is essentially your water's hardness or mineral content. So hard water has a high buffering capacity and soft water has a low buffering capacity. As far as the pH of that water is concerned, the buffering capacity of hard water is going to keep the pH high, conversely the low buffers in soft water will keep the pH low.
How To Lower pH
Because of the high buffering capacity of hard water you should never try to lower pH using chemical additives because all that happens is the pH falls because of the addition of the acid additive to the tank and then it promptly rises again because of the high buffering capacity of the hard water. This will really stress out your fish and will certainly kill them if done repeatedly.
You can safely use driftwood or peat moss in your tank which slowly release acids that lower the pH gradually. This means that you will have to replace the peat moss on a regular basis or the pH will go back up. Another method is to dilute your tap water with distilled water, thus reducing its mineral content (buffering capacity) and therefore its pH. Using this second method you can also fine tune the pH by using peat moss.
When lowering pH you need to carefully monitor it because the pH swings mentioned above can still occur.
How To Raise pH
This is much easier and not many people have this problem. All you have to do is add crushed coral or limestone rocks which dissolve increasing the hardness and the buffering capacity resulting in a higher pH. Again, pH raising products are not recommended because they can cause pH swings like the pH reducing products.
Conclusion
On the whole, pH is not something that the average aquarist needs to worry about. It should be a matter of acclimatising your fish to the pH that you are providing. The most important thing is not to subject your fish to vast pH variations. Anything more than a change of 0.2 in 24 hours is likely to stress your fish and make them susceptible to disease. Done repeatedly and it will eventually kill them.
If you must change the pH for a good reason then use natural methods rather than pH adjusting chemicals.
