10-28-2010, 02:32 PM
| || |
Welcome to Tropical Fish Keeping forum.
1077 is correct. If the pH is above 8, the water is probably quite hard, and lowering the pH will not be easy because the two are connected.
Hardness is determined by the amount of mineral, primarily calcium and magnesium, in the water, and is expressed as General Hardness in degrees GH or ppm GH. There is also carbonate hardness, expressed as KH (degrees or ppm again), and while the KH has no effect on fish (GH does), it acts as a buffer to keep the pH stable. Attempts to lower the pH in water with a fairly high KH will be futile and result in fluctuations which is far worse to the fish and will kill some outright. There are safe natural methods to lower pH but these involve lowering the GH/KH as well. I won't go into methods now.
If you could tell us the hardness we would have a better idea of what's involved and what fish may or may not work. As 1077 mentioned, some can adapt slowly, but there are some that cannot, and a pH above 8 is high. Livebearers, rainbow fish, rift lake cichlids and a few cyprinid fish species prefer basic hard water--though not all these in the same tank as they are not otherwise compatible.
Your water supply board should be able to tell you the GH and KH of your water, or they may have a website with this information. I wouldn't waste money on a hardness test kit unless you do intend to adjust the water later, as once you know the tap water hardness it is very unlikely to change. Aquarium conditions can naturally affect pH to some extent (depends upon the KH), but not hardness unless efforts are specifically made to do this.