kae
New member
http://www.bestfish.com/oldtank.html
Randy, are all informations in this article correct? Especially for this part...
The same processes that reduce ammonia to nitrite to nitrate also produce an abundance of hydrogen ions, which, if left to their own accord, acidify the water. In water from some sources that contain few "buffers" (ions that help stabilize pH by combining with excess hydrogen or hydroxyl ions), pH will tend to decline steadily just as the nitrate increases, and again regular pH testing may help alert the aquarist to impending trouble. However, in more heavily buffered water, an interesting but more threatening phenomenon occurs. As hydrogen ions are produced, they are immediately tied up by the buffer ion, and the pH remains roughly the same - until all the buffer ions are used up. At this point, the pH drops rapidly, and this sudden "pH crash" can be very damaging to fish.
If this process is allowed to continue (and a few, very hardy fish survive), another interesting biochemical phenomena occurs. At a pH of about 5.5 or less, the bacteria that usually convert ammonia to nitrite are inhibited, so ammonia levels begin to rise. Strangely, though, the low pH actually protects the remaining fish by keeping the ammonia in the non-toxic ammonia (molecular) form instead of the very toxic ammonium (ionic) form! It is not uncommon to see an old, neglected tank with a pH reading off the bottom of the chart, ammonia and nitrate off the top, and a couple of old-timer fish still swimming about.
Thank you very much.
Randy, are all informations in this article correct? Especially for this part...
The same processes that reduce ammonia to nitrite to nitrate also produce an abundance of hydrogen ions, which, if left to their own accord, acidify the water. In water from some sources that contain few "buffers" (ions that help stabilize pH by combining with excess hydrogen or hydroxyl ions), pH will tend to decline steadily just as the nitrate increases, and again regular pH testing may help alert the aquarist to impending trouble. However, in more heavily buffered water, an interesting but more threatening phenomenon occurs. As hydrogen ions are produced, they are immediately tied up by the buffer ion, and the pH remains roughly the same - until all the buffer ions are used up. At this point, the pH drops rapidly, and this sudden "pH crash" can be very damaging to fish.
If this process is allowed to continue (and a few, very hardy fish survive), another interesting biochemical phenomena occurs. At a pH of about 5.5 or less, the bacteria that usually convert ammonia to nitrite are inhibited, so ammonia levels begin to rise. Strangely, though, the low pH actually protects the remaining fish by keeping the ammonia in the non-toxic ammonia (molecular) form instead of the very toxic ammonium (ionic) form! It is not uncommon to see an old, neglected tank with a pH reading off the bottom of the chart, ammonia and nitrate off the top, and a couple of old-timer fish still swimming about.
Thank you very much.
